Polarization, Ideology and Voter Participation in European Parliament Elections, 2004-2024

Voters are less likely to participate in European Parliament elections than they are in national elections. Across almost every European country, turnout is higher in national contests than in EU contests, and these differential turnout rates are part of the reason why scholars traditionally view EP contests as second-order national contests. However, there is another facet of turnout that differs between EP and national contests, and which has received less attention – namely, that the nature of voters who participate in the two contests differs. While voters’ ideology plays little direct role in whether they participate in national elections, it does seem to matter for turnout in EP contests (see Fenzl et al. 2022). After controlling for a variety of factors predictive of turnout, voters who place themselves on the extremes of the left-right ideological scale are more likely to vote than those in the ideological center in EP elections, but not in national contests. In this paper, we use EES data to show that the strength of the relationship between ideological extremism and voter turnout has increased over the last five EP elections and has grown even stronger in 2024. We show that, unsurprisingly, these extreme voters cast ballots for extremist parties. We compare the rate at which they do so in national and EP elections. We also examine if the effect of extreme ideology on turnout is stronger in some countries than others, and specifically examine whether the pattern is stronger in countries with polarized party systems at the national level, a pattern previously observed in the 2014 and 2019 EP elections. We argue that, at least part of the trend towards more support for extremist parties and, therefore, greater polarization in the EP, comes from relatively higher turnout among ideological extremists in EP elections. The under-examined relationship introduces an interesting twist on the “second-order elections” story, which usually highlights the role of low turnout in EP elections, rather than the differential role of ideology in driving people to the polls. It suggests that in the future we may continue to see more support for ideologically extreme parties, resulting in a polarized European Parliament.