When parties matter: The conditional influence of party positions on voter opinions about European integration

While the literature on public support for European integration often suggests that political elites play an important role in shaping public attitudes toward the European Union, the empirical findings to date reveal an inconsistent pattern of political effects. The causal direction of this relationship has also been questioned. Using data from the Eurobarometer surveys, this article tests hypotheses to explain national, partisan, and individual-level variations in the strength of the party/voter connection. The results of a nonrecursive model demonstrate that party positions do influence electorate opinion, but that this effect varies with levels of disagreement among parties, party unity, issue salience, and party attachment. These results help to explain when and where political parties will exercise the greatest influence over public opinion.