Assessing the Clout of Radical Parties: Differences Between the Leverage of Radical Right and Radical Left over Mainstream Party Agendas in the European Parliament

Recent research has established that mainstream parties are not immune to niche parties’ agenda-setting efforts (Abou-Chadi 2014; Meguid 2005; van de Wardt 2014). Such ‘contagion effects’ are not only limited to the electoral arena (Abou-Chadi 2014; Meijers 2015; Van Spanje 2010), but can also be observed in the legislative arena (Otjes 2012; van de Wardt 2014). With the steady increase in the number of radical right and radical left parties and their seat share since Maastricht (Hakhverdian et al. 2013), the European Parliament (EP) provides a provoking case to test the influence of niche parties on mainstream parties. 

To investigate the divergent impact of radical left and radical right parties, we use original data to gauge the effects of articulation of topics through parliamentary questions on the mainstream parties. We expect that radical parties are always asking questions related to their core issues, and that mainstream parties are also asking questions on those same issues – however, we expect that as radical parties increase their attention by asking more questions on specific topics (relative to normal amount of questions asked by them on that topic), mainstream parties after radical parties have increased their attention also increase their attention to questions related to that topic. We thereby can gauge, first, whether radical parties are successful in influencing mainstream parties, and second, whether radical parties from either the right or the left are more successful in their influence on mainstream parties (cf. Meijers 2015).