Research project: The Causes & Consequences of Extreme Party Entry (Daniel Bischof)

Extreme candidates and parties - here defined as parties located at the very extremes of an imagined political left-right scale - are on the rise in democracies. Most recently, Germany experienced the entry of the extreme right party AfD into parliament (2017), while in Spain (Podemos) and Greece (Syriza) extreme left parties have entered parliament or enjoy governmental office. Such events of extreme party entry are destined to have crucial consequences for the political landscapes in modern democracies: established parties might adapt their agendas and positions in an effort to contain the voter potential of the new extreme competitor; extreme parties could influence media agendas in a disproportionately severe way; and public priorities and positions are likely to polarize as a result. While a rich and burgeoning literature has emerged investigating the rise of extreme parties (e.g. Kitschelt and McGann 1995; Mudde 2007; March 2011; Dunphy and Bale 2011), until today conceptual, theoretical and empirical challenges remain to be addressed.

First, the current literature focuses predominantly on the incremental rise of extreme parties. However, empirically extreme parties' electoral success frequently occurred sudden and unexpectedly (e.g. "Lijst Pim Fortuyn'' in the Netherlands). Therefore, I argue that scrutinizing the moment of extreme party entry into parliament is conceptually closer to the empirical development of extreme party success. As I will outline below this leads to novel theoretical mechanisms, reasons and consequences associated with extreme party success. In line with this first point, my project will advance existing research by providing a new theoretical perspective on these shock-like events. Theoretically I build on existing research in law and social psychology (Paluck, Shepherd, and Aronow 2016; Dahl 1957) to provide new arguments and mechanisms about the causes and consequences of extreme party entry. I will argue that the electoral success of extreme parties leads to shifting norms and a legitimization of extreme views. Thus, successful elections of extreme parties are likely to have severe consequences for party systems, the public and the media. Third, as Mudde (2013: 2) put it: "[...] in most cases the evidence (for the consequences of radical right party emergence) is illustrative at best, and correlation is taken for causation.’' I seek to address this methodolocial concern by providing causal identification strategies to rigorously test my causal claims. Investigating Western European democracies since 1945 I will exploit the discontinuities created by electoral systems to provide causal evidence for my theoretical arguments (e.g. by exploiting the discontinuities created by electoral thresholds and using Regression Discontinuity Design (Imbens and Lemieux 2008) and Synthetic Control Methods (Abadie, Diamond, and Hainmueller 2010)). To this end, the project aims to collect a rich amount of primary and secondary data on political parties, their lifetime cycles, electoral results and political institutions.

The novel theoretical perspective on extreme party success as well as the data and methods employed in my project will provide a rich and comprehensive understanding of the causes and consequences of extreme party entry. Therefore, I expect that the results of my research will diversify both political scientists' and the media's understanding of the role extreme party entry plays for the contemporary developments of Western democracies.


  • Workshop organization on Extreme Party Entrance in Zurich.


  • "Invasive parties: Do voters polarize when extreme parties enter parliament?" at King’s College London 2017.
  • Book manuscript
  • Creation of data-sets about party entrance in regional and national parliaments from 1945-2017 across 23 countries
  • Master Seminar: The Causes and Consequences of Extreme Party Emergence
  • Paper: Daniel Bischof & Markus Wagner. "Invasive Parties: Do voters polarize when extreme parties enter parliament?" Presented at EPSA 2017 (Milano), APSA 2017 (San Francisco). Workshops in Vienna & Aarhus.
  • Paper: with Markus Wagner. "How the AfD Affected Public Polarization in the German Länder."
  • Paper: "How Mainstream Parties Adapt their Agendas After Extreme Party Parliamentary Entry."
  • Paper: "The Randomness of Issue Ownership Theories: How External Shocks Drive Public Perception of Extreme Party’s Competence."
  • Paper: with Markus Wagner. "How Elections Legitimize Radical Ideologies: A Survey Experiment."


  • SNF Ambizione grant application