Mainstreaming the populist radical right? How exposure to immigration and EU media contents builds discursive opportunities for radical right populist parties

Radical-right populist parties (RRPPs) have been electorally successful in the last decades, but how does media exposure relate to their support? We argue that exposure to immigration and EU contents provide RRPPs with favorable discursive opportunities setting a public agenda advantageous to RRPPs as their supporters may use it to acquire information. To test this theory, we link web tracking data from 7,729 internet users in France, Germany, Italy, Spain, and the UK to their responses in repeated online surveys. Analyzing the contents of 150 million website visits allows us to measure media exposure more precisely than previous studies while at the same time linking these data to demographic attributes and political attitudes of participants. The results show that exposure to immigration and EU contents contributes to how supporters of RRPPs think about political issues.