In the study of European Union politics, it is commonplace to deplore the absence of electoral mobilization across national boundaries. One of the reasons the EU suffers from a democratic deficit, the argument goes, is that elections to the European Parliament serve as a projection screen for fundamentally domestic debates. The purpose of Gary Marks's and Marco Steenbergen's volume is to subject this common assumption to systematic empirical scrutiny. The central question the editors pose concerns what features shape the contestation over European integration. Specifically, can such contestation be captured by a small number of dimensions? And how do these dimensions relate to the domestic left/right cleavage over the role of the state in the economy?

The editors propose four theoretical models to answer these questions. 1) The international relations model (derived, for instance, from producer-group theories) posits a single dimension of contestation over European integration in which the left/right division is entirely irrelevant. 2) The Hix-Lord model (based on Political Parties in the European Union by Simon Hix and Christopher Lord, 1997) sees political conflict structured along two unrelated dimensions, support for versus rejection of European integration and left versus right politics. 3) The regulation model hypothesizes that conflict over integration can be reduced to the domestic left/right cleavage, with the Left calling for more European regulation and the Right for less. 4) The Hooghe-Marks model (developed in Multi-Level Governance and European Integration by Liesbet Hooghe and Gary Marks, 2001) claims that the pro/anti-integration dimension can neither be collapsed into the left/right dimension (as hypothesized by the regulation model) nor seen as entirely independent of left/right politics (as posited by the Hix-Lord model). Rather, specific aspects of integration can be mapped onto the left/right divide, producing two likely constellations: Left/pro-integration stands for “regulated capitalism” (p. 9) and right/anti-integration for neoliberalism.

The editors do not address the problem of conflicting theoretical interpretations of the main thrust of integration. Thus, the models assume specific interpretations of integration that are themselves subject to dispute. The international relations model sees integration primarily as a neoliberal undertaking that benefits exporters and hurts import-competing industries. By contrast, the other three models view integration as an attempt to regulate cross-border trade at the European level to substitute for protective and distributive measures traditionally provided by national governments. What integration actually means depends very much on specific policy issues and on the prevailing national status quo, a qualification that is at least considered in some of the contributions.

Still, it speaks to the intellectual cohesion of the volume that most of the empirical chapters directly address these four models. Four chapters each are devoted to individual-level attitudes and party competition, respectively, while two chapters deal with intermediary groups. Carefully triangulating methods and data, the chapters combine evidence from a wide array of sources, including Eurobarometer surveys of mass public opinion, European Election Study data, expert surveys of party positions, elite interviews, party manifestos, roll-call data, and event counts. Thus, the volume offers 10 empirically rich and theoretically ambitious chapters, each of which provides an original approach to the same overarching questions. The chapters do not, however, produce consistent findings. Rather than offer a definitive analysis of political conflict over European integration, the volume charts a bold intellectual agenda for further empirical analysis and replication of results.

The limited consensus that does emerge from (some of) the chapters can be summarized as follows: 1) Functional (left/right) and territorial (pro/anti-integration) competition are indeed largely independent, as hypothesized by the Hix-Lord model. 2) At the party level, functional and territorial competition produce an inverted U-curve, with extremist parties on both ends of the left/right spectrum opposing integration and mainstream parties supporting it. 3) A third dimension of “new politics” further complicates the pattern of contestation (see in particular the chapters by Hooghe et al., Jacques J. A. Thomassen et al., and Bernhard Wessels). Whereas the “traditional/authoritarian/nationalist” pole (p. 121) is strongly correlated with hostility to integration, its opposite, the “green/alternative/libertarian” pole (p. 121), varies across issues in its placement on the integration dimension. There is much room for follow-up studies that test the effect of this third dimension on specific policy areas.

All the empirical chapters are densely packed with data analysis deserving detailed comment. But a few stand out because they go beyond the four theoretical models that frame the volume. Both Leonard Ray and Adam Brinegar et al. map individual attitudes toward integration by taking into account the national status quo and resulting perceptions of relative losses and gains. Brinegar and colleagues test the effect of political-economic institutions on voters' attitudes toward integration. They argue that in universalist welfare states such as the Nordic countries, leftist voters tend to be Euroskeptic, whereas in residual welfare states, they expect to gain from more integration. Though their nested model of contextual effects and individual-level variables accounts for only a small percentage of the variation, this is a potentially productive line of analysis that may shed light on the apparent disconnect between the functional and territorial dimensions of contestation. Wessels examines the intriguing but separate question of whether European-level interest groups tend to form in anticipation of or reaction to EU institutional expansion. His answer, according to which new European interest groups tend to follow institutional reform, could be made more persuasive by reporting statistical significance levels (Table 9.1, p. 203). By focusing specifically on Eurogroups, Wessels brackets the territorial dimension of conflict in favor of exposing the new politics dimension alongside traditional left/right issues.

Despite the lack of consistent findings, European Integration and Political Conflict is required reading for students of contestation in an emerging polity. At least three lines of investigation invite follow-up studies: 1) the effects of national institutional variation on contestation, 2) issue-specific dynamics of contestation over integration, and 3) the role of new politics in structuring contestation in interaction with left/right and territorial politics.