A large part of the recent research agenda on electoral reform has been devoted to elucidating the historical determinants of the shift from majoritarian to proportional electoral systems in Western Europe at the beginning of the twentieth century. According to this literature, the adoption of proportional representation (PR) took place as a defensive move by established parties to limit the political influence of emerging socialist parties or as an offensive strategy by the same parties to reduce the vote-seat distortions that affected them in multiparty competitions under majoritarian electoral rules. Neither explanation accounts for the historical conditions that led to the initial adoption of PR in other regions of the world, where the reform was devised and enacted in the absence of increased party competition.
Analyzing the history of electoral reform in Latin America, this article argues that in a context of limited party competition, the initial adoption of PR was part of a strategy of controlled political liberalization fostered by authoritarian rulers. Within this general course of action, however, the dynamics of electoral change and the objectives of reformers varied depending on the nature of the authoritarian regime and the events that called into question the existing majoritarian electoral system. Based on these variables, this study shows that PR was promoted either by a dissident faction of the incumbent party to compete more effectively against the official leadership, by the old ruling party or a new reformist party to broaden support for the regime, or by military rulers to weaken a majority party whose policies they opposed. The article supports this argument with a comparative historical analysis of cases within and across each route to reform.
We start by discussing the main concepts and assumptions of the predominant explanations for the shift to proportional electoral rules in Western Europe. We then show the particular features of PR reform in Latin America, and analyze the general logic of reform and the three main paths to PR adoption in this region. We conclude by highlighting the contributions of this article to the comparative literature on electoral reform.
The Adoption of PR in Western Europe: Theoretical and Empirical Issues
Eleven Western European countries shifted from majoritarian to PR electoral systems between 1900 and 1921. Footnote 1 The trend started with Belgium in 1899, Finland in 1907, and Sweden in 1909, followed by eight countries that adopted PR in the aftermath of World War I (Caramani Reference Caramani2000). This period coincided with the expansion of male suffrage in several countries, the emergence of socialist parties, and the decision of trade unions to support working-class political platforms and candidates.
Based on these facts, the standard explanation of PR reform, initially proposed by Lipset and Rokkan (Reference Lipset and Rokkan1967) and Rokkan (Reference Rokkan1970), was that the expansion of male suffrage incorporated new voters, particularly from the working class, who in turn supported new parties that challenged the political and economic platforms of established parties. Footnote 2 In this scenario, established parties decided to protect their position against the rising popularity of socialist parties by introducing PR. Footnote 3 This explanation was later generalized and specified by Boix (Reference Boix1999, Reference Boix2010), who argues that PR was adopted in a changing electoral arena as a result of the threat that emerging socialist parties posed to established parties when the latter had relatively balanced electoral support and were unable to join forces.
Subsequent research has cast doubt on the “socialist threat” hypothesis as a single or main causal explanation of reform. Rokkan himself thought (1970, 157) that it did not apply to countries such as Denmark, Switzerland, or Belgium, where the drive to reform was motivated not so much by the electoral threat posed by socialist parties as by reformers’ desire to protect minorities in a heterogeneous society. Footnote 4 Some authors agree on the existence of a “second” route to PR, though not on Rokkan’s explanation of it. According to Calvo (Reference Calvo2009, 256), in the absence of an electoral threat from socialist parties, reform is explained by the strategic interest of established parties in reducing the vote-seat distortions that affected them when new parties entered the electoral arena and the territorial distribution of the vote was asymmetric. More generally, Andrews and Jackman (Reference Andrews and Jackman2005, 71) reject the socialist threat theory because of its implausible assumption that the old parties had sufficient information to act preemptively and shift to PR to minimize their seat losses. They claim that if we take uncertainty seriously, strategic politicians should have supported PR only when the seats-to-votes ratio of their party decreased under a majoritarian electoral system, regardless of whether this party was new or old, conservative or socialist.
In spite of considerable debate about their scope and use, the socialist (electoral) threat and the seats-votes disproportionality theories are by now the main established explanations for the adoption of PR in Western Europe. Footnote 5 A relevant question, then, is whether these theories can shed light on electoral reform in other regions of the world. PR has spread across many countries over time, and it has become the favorite choice for new democracies (see Reynolds et al. Reference Reynolds, Reilly and Ellis2005). Yet in many of these cases, the institutional transformation does not seem to be explainable by either the socialist threat or distortions in the seats-to-votes ratio of the main parties. The adoption of PR in Latin America illustrates this point well.
Most countries in Latin America, in a trend that seemed to follow their European predecessors, shifted from majoritarian to PR electoral rules between 1910 and 1950. This wave of reforms is, however, unrelated to the threat of socialism. In countries that held relatively competitive elections, such as Argentina, Chile, and Uruguay, socialist parties did emerge and compete against traditional parties during the first decades of the twentieth century. They also managed to capture a portion of the electorate from established parties (particularly liberal ones) in the most urbanized districts. Yet the socialists lacked the capacity to challenge these parties because their electoral support was small and their representation in parliament (if any) was meager. Footnote 6
The disproportionality between seats and votes cannot explain PR reform, either. This bias occurs when the sudden fragmentation of political competition under a majoritarian electoral system puts some of the preexisting parties at a competitive disadvantage. If these parties have a majority or plurality in parliament, they are likely to vote for a shift to PR to restore the previous equilibrium. In Latin America, however, in most countries where legislative elections were held before the adoption of PR, only one or two parties dominated the electoral arena. Chile was the only country that had true multiparty competition (see Gamboa and Morales Reference Gamboa and Morales2016). But this fragmented competition existed for more than two decades before PR was adopted, so the rise of new parties can hardly be associated with the reform.
From the perspective of the socialist threat and the seats-votes disproportionality theories, the adoption of PR in Latin America appears puzzling. Electoral reform took place after authoritarian periods without elections or with elections designed to favor the ruling party. Moreover, most reformers in this region established PR from a dominant position that they did not expect to lose in the near future. Why would these actors establish an electoral system that is supposed to improve the condition of minority or declining parties? Before we propose an answer to this question, we need to delve more deeply into the conditions under which PR was adopted in Latin America.
Features of PR Reform in Latin America
Similar to the situation in Western Europe, most Latin American countries experimented with various mechanisms intended to attenuate—without eliminating—the winner-take-all effect of majoritarian formulas before shifting to PR. Whenever elections were held, the typical formula was plurality rule in multimember districts with a “limited vote,” “cumulative vote,” or “incomplete list.” Footnote 7 Only a few countries had indirect elections or employed majority runoff formulas.
The trend toward PR started with Costa Rica in 1913, followed by Uruguay in 1917, Panama in 1925, and Chile in the same year. Footnote 8 By 1977, just before the expansion of electoral democracy in Latin America, 15 out of 18 countries had adopted proportional formulas. The few countries that had not adopted PR by that point have done so since. By 2000, no country in Latin America was electing members of the lower or single chamber of the legislature by a purely majoritarian system. Table 1 shows the year of the first adoption of PR in direct elections in each country of the region and the electoral system in place before reform.
Table 1 Proportional Representation in Latin America
a PR Hare in multimember districts with a distribution of remainders among individual candidates by plurality rule (Nicolau Reference Nicolau2012).
b PR Hare applied to districts that elected three or more legislators; plurality for districts of lower magnitude (Lehoucq and Molina Reference Lehoucq and Molina2002). Most candidates elected in districts of magnitude greater than 3.
c Mixed-member majoritarian system, with PR Hare for 100 out of 400 legislators (Molinar Horcasitas and Weldon Reference Molinar Horcasitas and Weldon2001).
Source: Authors, based on Colomer 2004; Golder 2003; Nohlen 2005; Wills-Otero and Pérez-Liñán 2005; and various country sources.
Although the details and content of the reform varied from country to country, there were common starting points. Three main features characterized the political environments in which PR was adopted in Latin America: the preexistence of universal (or quasi-universal) male suffrage, limited electoral competition, and presidential systems.
Preexistence of Universal (or Quasi-universal) Male Suffrage
According to Rokkan (Reference Rokkan1970, 157), the expansion of male suffrage was the crucial event that upset the institutional equilibrium of majoritarian electoral systems in Western Europe. This reform led to the incorporation of new voters, who, in turn, decided to cast their votes for new parties, increasing party competition. Some authors have argued that Rokkan’s hypothesis fits the sequence of events that led to the adoption of PR in Latin America (Wills-Otero Reference Wills-Otero2009). There are several reasons, however, why male suffrage expansion is unlikely to explain the emergence and spread of PR reform in this region.
As table 2 illustrates, one salient feature of PR reform in Latin America is that it had no apparent causal relationship with the de jure elimination of property or income qualifications for male voting. The initial formal expansion of male suffrage occurred in 13 Latin American countries well in advance of the adoption of PR. Footnote 9 On average, PR was established 50 years after the adoption of universal or quasi-universal male suffrage. Footnote 10 This is too long an interval to suggest a causal link between the two events. In three countries (Bolivia, Uruguay, and Venezuela), male suffrage expansion and PR adoption occurred simultaneously. In these cases, however, it would be more plausible to think that a third variable explained both reforms than assuming that the former caused the latter. Footnote 11 Finally, in two cases, Colombia and Costa Rica, formal universal male suffrage was adopted after PR.
Table 2 De Jure Male Suffrage Expansion and PR in Latin America
a Formal elimination of property, income, or tax qualifications for male voting at the national level.
Source: Authors, based on Colomer 2004; Nohlen 2005; and various country sources.
Another important reason to doubt a causal connection between suffrage expansion and PR reform is that in most countries voting qualifications were rarely enforced as stated in the law, and almost never implemented under conditions of meaningful electoral competition. In spite of the early legal adoption of direct, equal, and universal (or quasi-universal) male suffrage, the widespread use of violence and fraud generally discouraged political participation until other reforms granted voters some level of independence. One of these reforms was the secret vote, which is supposed to protect voters from social or political intimidation (see Przeworski Reference Przeworski2015). Yet in contrast to Western Europe, where secret voting was adopted in most countries before universal male suffrage, in Latin America it was established either at the same time or several years later. Footnote 12
Limited Electoral Competition
As we have seen, the main explanations for the introduction of proportionality in Western Europe assume the preexistence of an increasingly competitive electoral environment. The history of PR reform in Latin America does not conform to this pattern. In most cases the adoption of PR occurred in a nondemocratic year in which elections were held but competition was severely limited by authoritarian conditions. Table 3 shows whether the political regime was democratic or authoritarian, whether elections were held, and the nature of elections just before the shift from a majoritarian to a proportional electoral system in each country.
Table 3 Political Regime and Elections Before the Adoption of PR
a Political regime: Authoritarian or democratic nature of the regime that preceded the adoption of PR. Period starts at the beginning of an executive term and ends with the termination of that term or a change in the nature of the regime.
b Election: Parliamentary or Constituent Assembly election that preceded the adoption of PR.
c Election type:
1. Elections in which only one party is effectively allowed to win representation. Operationalized as elections in which the government party wins at least 75 percent of parliamentary or constituent assembly seats.
2. Elections in which voters can vote for opposition parties and the latter win legislative positions but rulers use coercive and unfair means to ensure their electoral and institutional predominance. Operationalized as elections in which the government party wins less than 75 percent of parliamentary or constituent assembly seats.
3. Elections in which voters face multiple options on ballots and incumbents do not abuse government power to prevent or reduce opposition victory.
Source: Authors, based on Boix et al. 2013 for the coding of political regimes; Howard and Roesler 2006 for the coding of elections; and Nohlen 2005, UCSD Latin American Statistics, and various country sources for the existence of elections and composition of parliament.
The vast majority of countries had authoritarian regimes at the time of reform. At the same time, all but three countries (Bolivia, Brazil, and Nicaragua) held elections in the immediate years before shifting to PR. In nine cases, those elections can be classified as hegemonic because only one party was effectively allowed to win representation. Footnote 13 In four cases, elections were contested but unfair, meaning that the ruling party allowed opposition parties to compete and win representative positions but resorted to fraud or repression to create an uneven field. Only two countries, Chile and Peru, experienced elections that were not only contested but also fair before electoral reform.
Table 4 shows whether the political regime was democratic or authoritarian, whether elections were held, the nature of elections, and the seat share of the party associated with the reformers in the first legislative or constituent assembly election when PR was implemented. Compared to preexisting majoritarian elections, it is clear that party competition increased and that even in an authoritarian regime, the first PR elections created more beneficial conditions for opposition parties. Only three of the postreform elections were hegemonic, while nine were competitive and six were free and fair. Yet it would be wrong to infer from this evidence that incumbents established PR in anticipation of an electoral environment that would become more competitive for reasons beyond their control (see Wills Otero Reference Wills-Otero2009, 36).
Table 4 Political Regime, Elections, and Partisan Position of Reformers After PR
a Political Regime: Authoritarian or democratic nature of the regime at the time when PR was first implemented. Period starts at the beginning of an executive term and ends with the termination of that term or a change in the nature of the regime.
b Election: Parliamentary or Constituent Assembly election in which PR was first implemented.
c Election type:
1. Elections in which only one party is effectively allowed to win representation. Operationalized as elections in which the government party wins at least 75 percent of parliamentary or constituent assembly seats.
2. Elections in which voters can vote for opposition parties and the latter win legislative positions but rulers use coercive and unfair means to ensure their electoral and institutional predominance. Operationalized as elections in which the government party wins less than 75 percent of parliamentary or constituent assembly seats.
3. Elections in which voters face multiple options on ballots and incumbents do not abuse government power to prevent or reduce opposition victory.
d Reformers’ Seat Share: percentage of legislative or constituent assembly seats of the party associated with the reformers in the first election using PR. Difference in seat share compared to the last election before reform is indicated in parentheses.
e No national parties. Percentage of seats of Vargas supporters in the 1933 Constituent Assembly.
Source: See table 3.
In ten cases the parties associated with the reformers won a majority or more than a majority of seats in the first legislative or constituent assembly election by PR. Of the four cases in which the reformers’ party did not win a majority, in only two (Colombia and Paraguay) its share of seats declined compared to its position before the reform. Furthermore, in four cases, the reformers had no parties representing them in the first election in which PR was implemented.
As we will see in more detail later, the relative position of reformers before and after electoral change suggests that the adoption of PR was itself part of a strategy that sought a more or less moderate increase in electoral competition by design. Most reformers in Latin America had the power to decide whether to liberalize the conditions of electoral competition, adopted PR from a dominant position, and when they had a party of their own, kept or improved their electoral advantage after implementing the reform.
Presidential Systems
In order to protect preexisting positions, reformers in Western Europe often decided to moderate the initial impact of proportional formulas by preserving indirect elections, appointment mechanisms, or majoritarian rules for a second chamber. They also resorted to other institutional rules to achieve the same goal, such as creating districts of small magnitude or establishing high legal thresholds. All these strategies are, of course, available in parliamentary and presidential regimes alike. The latter, however, have a structural feature, the independent election of the chief of government, which may affect the distribution of legislative seats regardless of the formula for electing legislators.
Presidential elections may “contaminate” legislative elections so that the number of parties winning votes and seats in those elections does not entirely depend on the system for electing legislators (see Cox Reference Cox1997). In these cases, whether or not the impact of presidential elections is restrictive depends on the formula to elect the executive and the electoral cycle. Specifically, the multiparty effect of PR may be moderated or even neutralized if plurality rule is used to elect presidents and at least some legislative elections are held concurrently with the presidential election (Shugart Reference Shugart1995). The predominance of presidential regimes in Latin America and the frequency with which they had plurality presidential elections and concurrent electoral cycles before the 1970s suggest that at the time when PR was introduced, the stakes of electoral reform may have been, in some cases, systematically lower than in Western Europe. Footnote 14
The preceding analysis makes clear that at a general level, most Latin American countries shared similar background conditions before adopting PR, and that these conditions were notably different from those prevailing in Western Europe. It also suggests that specific aspects of the cases, such as the nature of the regime that preceded reform or the partisan support that reformers expected after implementing the new electoral rules, are relevant for identifying various roads to reform. The novel explanation of PR reform in Latin America that we propose takes into account common and specific features of this process across cases.
Explaining PR Reform in Contexts of Limited Party Competition
The shift from majoritarian to proportional electoral rules in Latin America was an essential ingredient of a strategy of controlled political liberalization initiated by authoritarian rulers. These rulers were not always unified actors, and sometimes PR reform was a byproduct of internal divisions in the ruling party. Political liberalization was not an unconstrained choice, as it often occurred in response to growing social and political mobilization against the old regime. In the vast majority of cases, however, the adoption of PR was meant to maintain or create an advantage for the parties or factions that represented the interests of reformers. Only when reformers were able to foresee their lack of partisan support in future elections was their goal purely negative; namely, undermining the position of opponents.
In spite of this general pattern of reform, not all countries shared the same trajectory. We identify three major paths to PR, depending on the nature of the authoritarian regime and the events that called into question the existing majoritarian electoral system. Table 5 summarizes each path to PR reform in Latin America, indicating its antecedent conditions, triggering event, main reformers, reform strategy, and cases. Footnote 15
Table 5 Paths to PR Reform in Latin America
a Cases sharing antecedent conditions, triggering event, and reform strategy, but with variation in the identity of reformers. A provisional de facto government adopted PR in Brazil and the Dominican Republic.
b Honduras and Chile fit aspects of this path but differ from it in the antecedent conditions (Honduras) or in the triggering event (Chile).
When the preexisting authoritarian regime held regular though unfair elections between a government and a legal opposition party, the reform process was activated by the emergence of a strong dissident faction within the government party. In this context, the challenger faction supported PR to help it compete more effectively against the official leadership. When authoritarian rulers held no elections, elections were held at irregular intervals, or only one-party elections were tolerated, the reform took place as a consequence of growing extra-electoral opposition to the old regime, or its complete collapse. In this scenario, the old ruling party or a new reformist party adopted PR to signal the transition to a more open regime and to broaden support for it. When the authoritarian regime was a military dictatorship without partisan support, a previous conflict between the military and the majority party prompted reform. Under these circumstances, PR was adopted to weaken the future institutional influence of this party.
This framework is constructed on central elements of comparative historical analysis, which highlights the importance of causal configurations and contextualized comparisons in the explanation of an outcome of interest. We have also borrowed from this form of analysis its emphasis on the need to identify the empirical mechanism that connects observed causes to observed outcomes (Mahoney and Rueschemeyer Reference Mahoney and Rueschemeyer2003; Thelen and Mahoney Reference Thelen and Mahoney2015). For the purposes of our work, we argue that the diverse paths to PR reform were determined by the interaction between antecedent political conditions and the particular event that triggered the process in a given country. The event that set the process in motion also sheds light on the point in time under which the status quo was no longer sustainable, and the nature of the reform strategy. Footnote 16
To assess the plausibility of the proposed explanation and the mechanisms at work, we selected typical cases for each route to PR (see Gerring Reference Gerring2006; Gerring and Cojocaru Reference Gerring and Cojocaru2016). At the same time, these cases will be used to account for the differences across the three paths to reform (Skocpol and Somers Reference Skocpol and Somers1980). For the first route, we study Colombia and Uruguay; for the second, El Salvador and Bolivia; and for the third, Peru and Argentina. We claim that the countries selected for the first two paths are representative of a larger population of cases in which the identified strategy of reform was the main mechanism explaining the shift to PR. Footnote 17 To strengthen our argument, we examine those conditions under which majoritarian rules were maintained and those that activated their replacement by proportional rules. We also discuss how the path to reform determined the type of PR system adopted.
PR as a Strategy of Interfaction Coordination
Majoritarian electoral rules, such as plurality elections in single or multimember districts, are supposed to create two strong parties, which, in turn, have every incentive to keep the electoral system in place to exclude a third competitor (see Duverger Reference Duverger1954). Electoral preferences could change, however, in an asymmetric two-party system where majoritarian electoral rules may put both the opposition party and a dissident faction in the ruling party at a systematic disadvantage. In this context, continuous cycles of elections are likely to create problems of cooperation between parties, within parties, or both.
When the opposition party has a significant following and can mobilize resources, it may resort to political unrest to obtain reforms from the ruling party. Opposition demands for greater participation tend to take the form of calls for more transparent elections and the adoption of electoral rules that secure representation for minorities. In response, the ruling party may introduce mechanisms that moderate the winner-take-all effects of existing majoritarian rules, such as the limited vote or the incomplete list. If the opposition party hopes to increase its electoral support over time, renewed threats of rebellion may be made to induce further reforms. These reforms, however, are unlikely to take place while the ruling party remains relatively unified in its control of state institutions.
The event that may alter the status quo regardless of the strength of the opposition is the emergence of a strong dissident faction within the ruling party. As its position becomes more secure, a dominant government party would tend to lose internal unity over time. Whereas an opposition party is forced to keep some unity in order to compete effectively against the incumbent party, the latter is likely to experience divisions over distributive issues. A dissident faction may, for instance, consider that its share of power does not match its actual political strength. A majoritarian electoral system in which the official leadership has a predominant influence in candidate selection and the distribution of internal power exacerbates the conflict. In this context, a PR formula to allocate legislative seats not only between but also within parties may become attractive to the dissident faction of the government party, whether it remains in the party and obtains a greater share of power or eventually decides to compete against the official leadership as a separate political group. Footnote 18
The dynamics of electoral reform in Uruguay and Colombia illustrate this mechanism well. In both countries, two parties were formed in the mid-nineteenth century, and from the early years of the twentieth century on, competed in elections at relatively regular intervals. One of these parties, however, monopolized power through the use of fraud, coercion, and majoritarian electoral rules. Although the opposition’s capacity to disrupt political order induced the ruling party to guarantee a portion of seats to the minority, plurality rule in multimember districts remained in place as long as the government managed to keep its factional conflicts within limits. By contrast, the reform took place with the emergence of a strong dissident faction that weakened the ruling party’s capacity to compete as a relatively unified actor in the electoral arena.
The ruling Colorado Party in Uruguay shifted from complete to incomplete list plurality in multimember districts in 1898, allowing the main opposition party, the Nationals (or Blancos), to gain access to a third of the seats in a district if their lists won 25 percent or more of the valid votes cast (Pujol Reference Pujol1996; Faig Garicoits Reference Faig Garicoits1996). Similarly, Colombian conservatives passed an electoral reform in 1905 replacing the existing bloc vote by limited vote plurality, which allowed the main opposition party, the Liberals, to obtain up to a third of the seats in each district. Both reforms took place immediately after a civil war initiated, but not won, by the opposition and served as a concession by the government for the sake of preventing future revolts (see Maiztegui Casas 2013; Mazzuca and Robinson Reference Mazzuca and Robinson2009).
In neither case, however, did these reforms provide a permanent solution. Demands by opposition parties for more transparent regulation of the electoral process and the implementation of proportional formulas intensified in Uruguay in the 1910s and in Colombia in the 1920s. In both cases, episodes of political violence between the parties re-emerged in relation to these demands (see Maiztegui Casas 2013; Oquist Reference Oquist1980). This time, however, it was not civil war that upset the status quo in these countries; instead, it was the emergence of a strong factional division within the incumbent party. Footnote 19
The Colorado Party in Uruguay became deeply divided in 1913, when President José Batlle y Ordóñez (1911–15) proposed the adoption of a collegiate executive (colegiado) during the debates over the design of a new constitution. Although Batlle’s supporters were strong at the time, a dissident faction, the Riveristas or anticolegialistas, emerged and gained increasing electoral support over time (Fitzgibbon Reference Fitzgibbon1952, 618). The Nationals also opposed Batlle’s reform and found, in the results of the 1916 Constituent Assembly elections, a favorable environment for forging an alliance with the Riveristas for electoral reform. Footnote 20
When the Batllista faction failed to obtain a majority in the constituent body, Riveristas and Nationals joined forces to reject the colegiado and adopt universal male suffrage, secret vote, and proportional representation (Maiztegui Casas 2013, 198). Footnote 21 Supporters of Batlle, however, still maintained a comfortable majority in the legislature and won the 1917 congressional election. To overcome the stalemate, Nationals and Batllistas appointed a new bipartisan commission that agreed on a revised version of the colegiado in exchange for the secret vote and a d’Hondt formula in districts of medium magnitude (Chasquetti Reference Chasquetti2003; Buquet and Castellano Reference Buquet and Castellano1994). The key feature of the electoral system, however, was one that suited the interests of the challenger faction within the incumbent party and the opposition alike: the PR formula would be applied to distribute seats both between and within parties, using the double simultaneous vote system in force since 1910. Footnote 22
A comparable division within the incumbent party facilitated the approval of PR in Colombia. In 1929, the Conservative Party experienced a deep factional conflict that led to a split between the supporters of Guillermo Valencia and Alfredo Vásquez Cobo as candidates for the 1930 presidential election. This opened the way for a series of congressional alliances between dissident Conservatives and the Liberals. The Vasquistas supported the Liberals in approving a certificate of citizenship required to vote, while the Liberals supported the Vasquistas in the election of designados (substitutes for the president in the event of his temporary or permanent absence) in October 1929 (see Mayorga García Reference Mayorga García2013; El Tiempo 1929). In addition, in November the Vasquistas voted with the Liberals in support of PR. Footnote 23
One interpretation of this alliance is that the Vasquistas were trading PR for Liberal Party votes in favor of Vásquez Cobo (Mazzuca and Robinson Reference Mazzuca and Robinson2009, 313). This view fits the historical record because the Liberals lacked a presidential candidate until very late in the process. However, because it was uncertain whether the Liberals would deliver their votes to Vásquez Cobo, it is likely that dissident conservatives had other motives for supporting the electoral reform. Footnote 24
Given the existence of a plurality system with limited vote, two-thirds of the seats in each district would go to the candidates who received the most votes. With the numerical and institutional dominance of the official leadership, most candidates in most districts would belong to this faction, thereby placing the candidates of the dissident group at a great disadvantage. Footnote 25 Just as in Uruguay, a PR system applied to the distribution of seats across factional lists could help the dissident faction to compete more effectively against the official leadership.
This was exactly the type of PR adopted by Act 31 in the Colombian Congress. This law established a Hare proportional formula with largest remainders in districts of medium magnitude, with the peculiar feature that it would be implemented to distribute seats between “parties or group lists” that obtained a share of votes above a full quota (Delgado Reference Delgado2002, 105). In other words, the introduction of proportionality was meant to serve not only the interests of the opposition but also those of the challenger faction within the ruling party.
PR as a Strategy to Increase Regime Support
In a context of growing electoral competition, an incumbent party that achieves a dominant position thanks to majoritarian electoral rules may react defensively if new parties start to capture a significant portion of its vote. In particular, this party may take advantage of its power at the moment and shift to PR to prevent absolute defeat in the future. This logic does not hold under some authoritarian conditions. When there is potential government influence over election results and no established opposition exists, the old ruling party or a new reformist party that is confident about winning future elections may adopt PR simply to coopt opponents and broaden support for the regime.
As students of nondemocratic politics have pointed out, authoritarian leaders enhance the regime’s survival when they mimic the formalities of a representative system and allow the opposition to participate in legislative elections (see Gandhi Reference Gandhi2008). Yet this strategy is not likely to work if the incumbent party wins all or almost all legislative seats or if it annuls elections every time electoral support for opposition parties grows. Under these conditions, the opposition may withdraw from participation in elections. The depletion of loyal opposition will, in turn, deprive the regime of any pretense of democratic representation and induce opponents to adopt nonelectoral means to achieve power. In this scenario, the ruling party may decide either to liberalize electoral contests in a more meaningful way or to maintain a highly exclusionary political system.
If the ruling party decides to liberalize, it is likely to adopt a restricted form of PR to persuade opposition parties to compete without risking its electoral advantage. However, autocrats may also fail to liberalize in time if they underestimate the political strength of opponents. As a consequence, a new party or coalition with popular support may succeed in overthrowing the old regime by force. In this situation, the triumphant party or coalition is also likely to adopt PR, not out of fear of losing future elections but to distinguish itself from former rulers and broaden support for the new (not necessarily democratic) regime. As when the former ruling party enacted the reform, the type of PR adopted in this context is expected to benefit the largest party, by design.
This scenario depicts the first introduction of PR in most countries of Latin America, and the history of electoral reform in El Salvador and Bolivia is representative of the majority of cases included in this path. In contrast to Colombia or Uruguay, neither El Salvador nor Bolivia had, in the past, developed a tradition of regular electoral contests between a government and a legal opposition party. Majoritarian elections and government control allowed only one party to win, or if more than one party competed, elections were suspended or annulled when an opposition party increased its support above acceptable levels. Whereas in El Salvador the ruling party shifted to PR in the face of growing political and social opposition to its hegemony, in Bolivia a new revolutionary party that displaced former autocrats from power decided on the reform. In both cases, however, PR was part of a strategy of controlled liberalization to increase support for the new regime.
Beginning in the 1950s, authoritarian regimes in El Salvador shifted from personalistic military dictatorships to institutionalized authoritarian regimes, holding elections that only the government party was effectively allowed to win. The first of these parties, founded in 1949, was the military-sponsored Partido Revolucionario de Unificación Democrática (PRUD), which, through the use of a highly majoritarian multimember district plurality system and government-controlled elections, won virtually all seats in the legislative assembly between 1952 and 1960 (see Nohlen Reference Nohlen2005). By the late 1950s, however, the status quo had been altered. In 1959, the government of Lieutenant Colonel José María Lemus started to face growing social and political opposition from students and a newly created party, the leftist Partido Revolucionario de Abril y Mayo (PRAM). In addition, in 1960, the centrist Partido Demócrata Cristiano was formed to oppose the regime (see Bethell Reference Bethell1990, 263).
In this context, and after a series of coups and countercoups, Colonel Julio Rivera took control of the situation and replaced the PRUD with a new military-sponsored party, the Partido de Conciliación Nacional (PCN). Although the PCN was a successor of the PRUD, the strategy did not consist simply of changing the name of the ruling party. After convening a constituent congress in which it won all seats, the PCN enacted a new constitution in 1961 and a new election law in 1963 that established PR for legislative elections for the first time in the country. Historical analyses suggest that the purpose of this reform was clearly to increase the number of seats for the opposition, especially the moderate opposition, such as the PDC (see White Reference White1973, 198; Bethell Reference Bethell1990, 263–64).
Under the new electoral system, the government party was able to maintain a comfortable legislative majority of 61 percent while allowing the PDC to win more than 27 percent of the seats in the 1964 election (see Nohlen Reference Nohlen2005, 285). The incumbent party advantage was due not only to government control of voting but also to the type of PR adopted: a closed-list Hare formula applied to a very small assembly of 52 members elected in 14 multimember districts with a low average magnitude of 3.7.
Similar to El Salvador, neither civilian nor military dictatorships in Bolivia managed to form a strong ruling party during the early decades of the twentieth century. The first attempts to form an official party occurred in the 1940s, with the decline of traditional liberal and republican parties and the emergence of new reformist parties that embraced radical ideologies (see Klein Reference Klein2003, 186). The most important of these parties was the Movimiento Nacionalista Revolucionario (MNR), founded in 1942. Thanks to the support of the de facto government installed in 1943 and the use of plurality rule with limited vote in multimember districts, the MNR became the largest party in the 1944 congressional elections, winning 66 of 136 seats (Abecia Valdivieso Reference Abecia Valdivieso1999, 112). However, after a new coup in 1946, organized by forces allied with traditional parties, the MNR was displaced from power and its leaders exiled.
In spite of state repression and electoral fraud, the MNR was not only able to compete in the 1947 and 1949 legislative elections but also to win the 1951 presidential election (Klein Reference Klein2003, 205). Yet its return to power could only take place by force. The incumbent government asked the military to intervene to annul the 1951 election, suspend Congress, and outlaw the MNR. In response, the MNR forged an alliance with the Central Obrera Boliviana (COB) and organized a revolution that overthrew the de facto government.
Although the MNR did not intend to establish a democracy, it did adopt a series of democratizing measures, such as universal suffrage. In order to differentiate itself from previous authoritarian governments, the new reformist party also pursued a strategy of controlled political liberalization. A key component of this strategy was the adoption of PR, to be implemented for the first time in the 1956 congressional election (García Montero Reference García Montero2003). In this and subsequent elections until its overthrow in 1964, the MNR was able to hold a hegemonic position, always winning more than 75 percent of the legislative seats. However, parties that opposed the MNR and had had almost no institutional presence in the past, such as the Falange Socialista Boliviana (FSB), were allowed to compete in all elections and win a minority of legislative seats.
As in the case of El Salvador, the type of PR implemented in Bolivia had the potential to incorporate some opponents into the political system without putting the dominance of the incumbent party at risk. The MNR adopted a PR system with a strong bias in favor of large parties. Although the average district magnitude was medium (7.5), a PR Hare formula was applied to elect a very small assembly of 68 members using a system known as double quotient, which set a high electoral threshold for minority parties to have access to the distribution of seats. Footnote 26 In addition, in 1956 the ruling party replaced the absolute majority rule that had been in force since the nineteenth century to elect presidents with a plurality formula, implemented every four years in concurrent congressional elections with a midterm partial renewal. This combination of rules (in addition to the potential use of nonlegal resources to create an uneven field) secured the government party a comfortable majority position.
PR as a Strategy to Debilitate Opponents
In the general literature on electoral change, it is often assumed that the main actors in this process are parties and party leaders. This assumption is misplaced, however, in some authoritarian contexts. This is particularly the case with many military dictatorships that failed to create a strong government party or forge a stable alliance with preexisting parties. In Latin America, only 29 percent of the military regimes in existence between 1900 and 1990 were able to rely on partisan support to organize their rule (see Negretto Reference Negretto2014). In this situation, when the regime adopted new institutions, military rulers should be considered the main reformers.
The intervention of the military and its influence on the domestic politics of many countries of Latin America is well documented (see Rouquie and Suffern Reference Rouquie and Suffern1998). This influence has been visible when the military acted as arbiter in electoral disputes between parties, siding in favor of one against another, or when it intervened to prevent certain parties from taking power. However, the military has also had a less noticeable but crucial impact on the development of interparty competition when it acted as reformer of the rules of the electoral game. This has been the case when military rulers deposed a civilian government, but before withdrawing from power, implemented electoral or constitutional changes that affected the course of partisan competition in the future.
One of the lasting legacies of military rulers as electoral reformers in some countries has been the introduction of PR. This occurred in countries where the military lacked a party of its own or a reliable partisan ally, and majoritarian electoral rules worked systematically in favor of a civilian party whose policies it opposed. Under these conditions, military dictators did not limit themselves to deposing the party from power or annulling the election that its candidates won; they also adopted PR as a strategy intended to debilitate the largest party, with the possible additional effect of strengthening minority parties whose programs were closer to, or at least not openly against, their interests. Footnote 27
Argentina and Peru exemplify this route to PR. Both countries share a past of military interventions in which military rulers acted as arbiters of partisan competition. Yet unlike some Central American countries, such as El Salvador or Guatemala, the military in Argentina and Peru did not perpetuate itself in power by creating a successful party of its own, nor did it manage to form a permanent alliance with one of the main parties in the country. In addition, these countries experienced a process of democratization in which majoritarian electoral rules worked in favor of, or had the potential to increase, the influence of a civilian party whose policies were perceived as harmful to the military.
In the case of Argentina, PR was first introduced as a byproduct of the conflict between the military and the Peronist Party (PP). After Juan Perón was elected president in 1946, the PP (officially created in 1947) gained almost absolute control of the state between 1948 and 1951, due partly to a plurality incomplete list system for elections, which provided the party with disproportionate institutional power. Antagonized by several of Perón’s policies, the military decided to overthrow his government in 1955. The new de facto government abrogated the constitution enacted in 1949 and convened a constituent assembly in 1957 (see Padilla Reference Padilla1986, 583). The military banned the PP and, for the first time, established a system of proportional representation to elect delegates to the convention.
Although the military dictatorship actively promoted the adoption of PR for all future elections, to avoid repeating the Peronist experience, the main opposition parties represented in the 1957 Constituent Assembly defended the previous majoritarian system, expecting that they might hold the majority in the future (see Spinelli Reference Spinelli2012). Over time, however, the military’s preference prevailed. In a context of permanent conflict between the military and the PP and cycles of democracy and authoritarian rule, the same formula that had been designed in 1957 was used to elect deputies in 1963 and 1965. As of 1972, again under the influence of a military dictatorship, PR became a permanent feature of congressional elections in Argentina.
In Peru, a military junta adopted PR in 1962, following a coup aimed at preventing Víctor Raúl Haya de la Torre of the Partido Aprista Peruano (PAP) from taking power after he won a presidential election by a small margin of votes (see Tuesta Soldevilla Reference Tuesta Soldevilla2001). As in Argentina, the shift from majoritarian to proportional electoral rules took place against a background of intense political conflict between the military and a popular party. Although the PAP never reached the level of electoral support and following of the Peronist Party, it had been the largest party in Peru since the mid-1940s. Short of banning the party (something that had been attempted before, under the dictatorship of Manuel Odría), it was impossible to prevent the Apristas from having a strong legislative influence.
Peru had had plurality elections with incomplete list before the adoption of PR. Given the instability and intermittent fragmentation of the Peruvian party system, these rules were unlikely to create a hegemonic winner in most districts. However, the election of members of Congress concurrently with the election of presidents by a formula close to plurality (33 percent) made it possible for the party of a popular presidential candidate potentially to win a majority of districts, and thus a majority (or something close to a majority) in Congress. To prevent this from happening, the military intervened to annul the 1962 elections and shortly thereafter adopted a PR system to be implemented for the first time in the legislative elections of June 1963 (see Guibert Patiño Reference Guibert Patiño2014, 11). In this election, although the PAP won the largest legislative share with 40 percent of the seats, it was sufficiently short of a majority to be unable to control the assembly.
As in the previous cases analyzed here, the path to reform and the rationale for change had an impact on the type of PR adopted. If military rulers adopted PR to reduce the power of a popular party they opposed, the new electoral rules should have been relatively inclusive at the time. This is, in effect, what happened. In the case of Argentina, the first implementation of PR in 1957 was used to elect a 205-member constituent assembly selected by a closed-list d’Hondt formula in multimember districts with an average magnitude of 8.9. In Peru, a closed-list PR d’Hondt system was implemented in 1963 for the election of an assembly of 140 legislators (larger than the 2016 Peruvian Congress) in multimember districts with an average magnitude of 5.8.
Conclusions
The relationship between electoral systems and party systems is not unidirectional. It is precisely because plurality rule tends to maintain two-party systems and PR multipartism that large or ascending parties are likely to prefer majoritarian electoral systems and small or declining parties tend to support PR formulas. This is the main historical lesson from the adoption of PR in Western Europe. With the extension of suffrage to the male population and the incorporation of new voters, third parties emerged in restrictive electoral systems. In this context, either a re-equilibration occurred and the new parties disappeared, or established parties shifted to PR. In other words, the origins of PR in Western Europe are associated with growing levels of electoral competition.
The adoption of PR in Latin America does not fit this scenario. In the first place, PR reform in this region was not related to the formal extension of suffrage to all or a majority of males. Although the number of voters tended to increase over time, de jure universal or quasi-universal male suffrage occurred, on average, many decades before PR adoption. At the same time, although elections were held in most countries before electoral reform, they took place under authoritarian conditions that severely limited partisan competition.
We have argued that the initial adoption of PR in Latin America was part of a strategy of controlled political liberalization initiated by authoritarian rulers. We have also proposed that within this general framework, specific paths to reform varied, depending on the nature of the authoritarian regime and the events that called into question the maintenance of the existing majoritarian electoral system. Using this theoretical perspective, we have shown, with comparative historical data, that the shift from majoritarian to proportional electoral rules was promoted either by a dissident faction of the incumbent party to compete more effectively against the official leadership, by the old ruling party or a new reformist party to broaden support for the regime, or by military rulers to weaken a majority party whose policies they opposed.
This article contributes to the comparative literature on electoral reform in several ways. It provides a novel, historically grounded explanation for the emergence of PR in Latin America that could be used to shed light on the adoption of PR in regions outside Western Europe. In addition, although the historical routes to PR in Latin America differ from those followed in Western Europe, a key aspect of the reform is similar. Although PR eventually promoted greater political inclusion in both contexts, the new rules were often introduced by the old elites to maintain power and limit the influence of competitors. The development of a more ambitious theoretical framework, one that is able to include important electoral reforms in established and new democracies, is badly needed in comparative electoral research. This article is, we hope, a contribution toward that goal.
