Populist Conspiracy Framing: The Impact of Party Cues in Explaining Conspiracy Beliefs

How effective is populist party conspiracy framing? There is an extensive literature on how party cues influence public opinion and there is evidence that populist parties engage in conspiracy framing, but little is known about how such framing influences conspiracy beliefs. This paper seeks to fill this gap by investigating how cues of populist and non-populist parties shape respondents' susceptibility to conspiracy explanations. Specifically, we examine whether political party agreement or disagreement can influence belief in conspiracies related to immigration, climate change, and the COVID pandemic. To this end, we conduct an original survey experiment in four European democracies: Austria, Italy, France and Switzerland. The treatment group is shown fictitious social media posts containing conspiracy claims about the three issues. Additionally, respondents receive information that either (1) their most preferred party or (2) their least preferred party agrees or disagrees with the statement and are asked to indicate their own position. Our results shed light on whether and how opinion formation about respondents' preferred party influences their susceptibility to conspiracy beliefs, on the difference between populist and non-populist parties, and on whether the least preferred party produces a backlash effect. We also examine how these effects vary across issues and countries.