From Second-Order to First-Order? Investigating Voter Decision-Making in the 2024 European Parliament Elections

European Parliament (EP) elections have traditionally been analyzed as second-order elections. However, with the increasing politicization and polarization of EU integration in recent years—driven by contested European migration policies and the war in Ukraine—researchers have begun to explore whether EP elections are evolving into first-order contests. Evidence suggests that voters apply different criteria and heuristics when deciding how to vote in EP elections. While some still view these elections as an opportunity to reward or punish their national government, others base their decisions on issues more specific to EU politics and the dynamics of European party competition. This paper seeks to deepen the understanding of variations in voter decision-making during European elections through an experimental approach. In our survey experiment, participants were confronted with different primes before answering questions about their political attitudes and intended voting behavior. Some were presented with European issues, EU performance, and European conditions, while others were asked about national issues, the performance of their national government, and national conditions. This experimental design allows us to disentangle second-order motivations from first-order motivations more effectively. We hypothesize that voters will vary significantly in their responses to these primes and in the extent to which they use EU-specific attitudes to inform their political judgments and voting decisions. The online survey experiment was conducted in May and June 2024 during the three weeks leading up to the EP election in Germany. A total of 6,230 participants were recruited through both online and offline channels. The survey included a broad range of measures, such as party preferences, attitudes toward European Spitzenkandidaten, opinions on the Ukraine war and migration issues, economic perceptions, national and European identity, knowledge of national and EU politics, and attitudes toward further European integration. These measures allow us to analyze the various motivations influencing voter behavior and their impact on voting decisions in the 2024 EP election. Preliminary results reveal that the effects of the primes (national versus European focus) varied widely across voters. Many participants - particularly those with lower political knowledge, strong partisan loyalties, and polarized views on national politics - based their voting decisions primarily on their assessments of national politics, regardless of the primes. In contrast, voters with higher political knowledge, greater educational attainment, and less extreme national attitudes were more responsive to the European-focused primes, incorporating European issues into their decision-making processes. By studying these differences between voters, this paper offers new insights into the decision-making processes of voters in EP elections and examines the conditions under which these elections might evolve into first-order contests.