Parties’ Twitter discourse on ruling with anti-establishment parties. Who wants to do it with whom and why?

Anti-establishment politics is on the rise: both left-wing and right-wing parties challenging the political establishment have performed well at the ballot box throughout Europe (Krause & Wagner, 2019). However, a paradox seems to be present: despite their electoral success, anti-establishment parties rarely make part of a government coalition (Akkerman & De Lange, 2012; Harteveld et al., 2021). We can discern two potential explanations for this observation. First, mainstream parties may be reluctant to rule with anti-establishment parties for a wide variety of reasons. Second, anti-establishment parties may be hesitant to carry government responsibility and join a coalition. Still, more recently several mainstream parties have ruled with anti-establishment parties from the radical left (e.g., Greece, Italy) and right (e.g., Austria, Norway). Hence, the question remains open (1) under what conditions mainstream parties are willing to rule with anti-establishment parties and, in parallel, (2) under what conditions anti-establishment parties are willing to accept government responsibility. Which reasons to either include or exclude anti-establishment parties from government prevail and how does the ideology of anti-establishment parties play a role? To shed light on these questions, this study reports findings of a longitudinal content analysis (2006-2020) of Twitter claims of both mainstream and anti-establishment parties on their preferences regarding coalition formation in Austria, Belgium (Flanders and Wallonia) and the Netherlands. Preliminary findings show that mainstream parties that are ideologically close to either a right-wing or left-wing anti-establishment party display less reluctance to join a coalition with it, despite its questionable ideology. In general, ideological reasons seem to trump policy-related or strategic reasons to motivate inclusion or exclusion of anti-establishment parties in/from government. Most anti-establishment parties, however, consequently emphasize in their Twitter claims that they are willing to carry government responsibility, but that they are denied this opportunity by their mainstream counterparts. They commonly claim that the signal of voters for change should be respected, that exclusion undermines democracy, is an instrument of mainstream parties to silence a large segment of citizens and helps their political opponents. Implications for coalition formation theory and democratic legitimacy are discussed.