Responding to the left: the effect of far-left parties on mainstream party Euroskepticism

Do far-left political parties influence the level of Euroskepticism among mainstream political parties within that same party system? This study seeks to address this question by building on previous work that has examined the effect of both far-left and far-right Euroskeptic parties on mainstream party positions regarding the EU. We theorize that when far-left parties place an emphasis on state control over the economy, mainstream parties in the same party system are less supportive of the EU. To test our theoretical expectations, we use data from the Comparative Manifestos Project in 25 EU member states from 1958 through 2015. The analysis indicates support for the hypothesis that when far-left parties place greater emphasis on a need for state control of the economy, mainstream parties in that party system are more Euroskeptic. Our findings have important implications for understanding the nature of political party dynamics both generally, and more specifically in the European Union.