Increasing affective polarization in Europe: Loathing across party lines or against populists?

There appears to be a widespread understanding in the media as well as in academic circles about an increased hostility across party lines (Gidron, Adams and Horne 2019). Despite the diagnosis, not many scientific studies have tested this hypothesis, in particular over the longer time period. Using data from the Comparative Study of Election Systems (waves 1 to 5) covering 20 years and 22 European countries, this article measures the demand-side of affective polarization, or how citizens see different parties in their country’s political landscape, and how this has changed over time. We test two wide-spread assumptions: 1) that there has been an increase in affective polarization across party lines over the last decades in European societies; 2) that this rise is caused by the growing success of populist parties among the public. We look specifically at European countries since the two statements are used to describe the political situation in the region and Europe offers a variety of cases for a comparative perspective. The study uses network analysis to capture and assess the influence of specific parties on the increased polarization as well as the rise of affective polarization in European party systems more generally. This method allows for a more complex, multidimensional and multifaceted approach and is better suitable for measuring polarization in European multi-party systems than currently available measures. In a second step, the article assesses how the emergence and/or electoral success of populist parties influenced the level of affective polarization in chosen countries (chosen according to the level of affective polarization and presence of prominent populist parties), as well as whether an increase in affective polarization would have taken place without these populist gains. Finally, the study corroborates previous research on the directionality of partisan loathing showing as the latter counter-intuitively originates from non-populist.