With a proliferation of scholarly work focusing on populist, far-left, and far-right parties, questions have arisen about the correct ways to ideologically classify such parties. To ensure transparency and uniformity in research, the discipline could benefit from a systematic procedure. In this letter, we discuss how we have employed the method of ‘Expert-informed Qualitative Comparative Classification’ (EiQCC) to construct the newest version of The PopuList (3.0) – a database of populist, far-left, and far-right parties in Europe since 1989. This method takes into account the in-depth knowledge of national party experts while allowing for systematic comparative analysis across cases and over time. We also examine how scholars have made use of the previous versions of the dataset, explain how the new version of The PopuList differs from previous ones, and compare it to other data. We conclude with a discussion of the strengths and limitations of The PopuList dataset.

Do populist radical right (PRR) parties fuel affective polarization? If so, how and under which circumstances? Based on a comparative cross-country analysis covering 103 elections in 28 European countries and an examination of longitudinal data from the Netherlands, we show that PRR parties occupy a particular position in the affective political landscape because they both radiate and receive high levels of dislike. In other words, supporters of PRR parties are uniquely (and homogeneously) negative about (supporters of) mainstream parties and vice versa. Our analyses suggest that these high levels of antipathy are most likely due to the combination of these parties' nativism and populism – two different forms of ingroup–outgroup thinking. Our findings also suggest that greater electoral success by PRR parties reduces dislike towards them, while government participation appears threatening to all voters except coalition partners.

Canonical theories of opinion formation attribute an important role to affect. But how and for whom affect matters is theoretically underdeveloped. We establish the circumplex model in political science as a theory of core affect. In this theory unconscious emotional processes vary in level (arousal, measured with skin conductance) and direction (valence, measured with facial electromyography). We theorize that knowledge, attitude extremity, and (in)congruence with political rhetoric explain variation in affective responses. In a large lab study (N = 397), participants watched video clips with left-wing or right-wing rhetoric on prominent issues. We find that people with extreme attitudes experience more arousal in response to political rhetoric and that political rhetoric incongruent with prior attitudes evokes negative affect. Moreover, we show that affective responses lead to opinion change, independent of self-reported emotions. We conclude by setting a research agenda for the alignment between affective and cognitive components of emotions and their consequences.

Various scholars have argued and demonstrated that Western European populist parties have something in common. Although these parties adhere to various ideologies and employ different organizational forms and political styles, they all endorse a similar set of ideas concerning the relationship between the people and the elite. Yet despite our increasing knowledge about these parties, so far we know only very little about populist voters. Do the voter bases of populist parties also have something in common? To answer that question, I focus on the electorates of 15 prototypical populist parties from 11 Western European countries. I show that, in contrast with widely held beliefs, the electorates of populist parties do not always consist of individuals who are more likely to be ‘losers of globalization’ with Eurosceptic attitudes, low levels of political trust, and preferences for (more) direct democracy. This suggests that ‘the’ populist voter does not exist.

There are different area-based bodies of literature on populism, which generally define the concept in slightly different ways. As a result, the term ‘populism’ has been attached to a wide variety of political actors, from Perot in the US to Berlusconi in Italy, and from Perón in Argentina to Le Pen in France. Is it an unfortunate coincidence that the same word has been used for completely different parties and politicians, or is it possible to discern the lowest common denominator that these actors share? By means of a comparison of six cases, based on a most-different systems design, I demonstrate that populists in different times and places have four characteristics in common: (1) they emphasize the central position of the people; (2) they criticize the elite; (3) they perceive the people as a homogeneous entity; and (4) they proclaim a serious crisis. These four characteristics constitute the core elements of populism.