National Party Politics and Supranational Politics in the European Union: New Evidence from the European Parliament

Political parties play an important role in structuring political competition at different levels of governance in the European Union (EU). The political parties that contest national elections also participate in the EU legislative institutions, with the governing parties at the national level participating in the Council of Ministers and a broad range of national parties represented in the European Parliament (EP). Recent research indicates that national parties in the EP have formed ideological coalitions -- party groups -- that represent transnational political interests. These party groups appear to manage legislative behavior such that national interests -- which dominate the Council of Ministers -- are subjugated to ideological conflict. In this paper, we demonstrate that the roll-call vote evidence for the impact of party groups in the EP is misleading. Because party groups have incentives to select votes for roll call so as to hide or feature particular voting patterns, the true character of political conflict is never revealed in roll calls.