Mainstream Sell-Outs? How Collaboration with the Radical Right Changes Perceptions of Party Positions on Immigration

European mainstream right parties are increasingly choosing to include radical right parties in coalition governments or other types of stable and committed cooperation. How does this cooperation affect voters’ perceptions of party positions? This article examines whether coalition signals have a significant impact on voters’ perceptions of the specific policy issues that were at stake in the bargaining process. More specifically, does the issue ownership of the radical right cause voters to perceive mainstream parties as radicalizing on immigration issues pertaining to asylum and multiculturalism? I compare the perceptions of Dutch parties before and after two coalition formations that (formally and informally) involved a radical right party: the coalition with the List Pim Fortuyn in 2002 and the support agreement with the Freedom Party in 2010. Furthermore, I examine the long-term effects of the Danish mainstream right government's reliance on the support of the radical right Danish People's Party in 2001–11.