Towards an Integrative Theory of Mainstream Right Radicalization (MRR)

As far-right parties reshape European politics, increasing attention has been devoted to their influence on mainstream right parties — particularly their gradual adoption of far-right policy positions characterized by exclusionary, nationalist, and illiberal tendencies. While there is sufficient empirical evidence demonstrating this radicalization, most studies are cross-case quantitative analyses that fall short of explaining how mainstream right parties evolve within their specific national contexts. This paper investigates the radicalization of European mainstream right parties, focusing on how their policy positions evolve on two issues — migration and foreign policy — that have gained salience and polarized electorates over the last decade. It develops a framework focusing on issue salience, policymaking autonomy, and liberal-democratic commitment to explain under what conditions mainstream right parties shift from policies associated with liberal democracy towards policies associated with illiberal democracy. Using a qualitative, exploratory case study design grounded in within-case process tracing, the research examines two contrasting cases: the Netherlands, representing a “typical case” of mainstream right and far-right interactions resulting in a coalition government, and Romania, a “diverse case” highlighting variations in these dynamics.