The transition to globalized knowledge economies in recent decades have accelerated economic and social change across the globe.1 European democracies have been no exception to these developments. They have experienced rapid structural changes to their economies, increased social inequality, new social cleavages (see, for example, Chapter 11) and growing ethnic diversity resulting from migration. These changes have had political repercussions, including growing support for politically extreme challenger parties and the rise of populist political entrepreneurs in many countries (Iversen and Soskice 2019; Proaño, Peña and Saalfeld 2019; de Vries and Hobolt 2020). Some authors have even argued that the nature of partisan conflict itself has changed. While traditionally most European party systems were dominated by a socio-economic conflict between left-wing parties supporting tax-funded expansion of the welfare state and Keynesian economic policy and right-wing parties advocating a free-market economy (Laver and Hunt 1992), new voter coalitions have emerged (Hillen and Steiner 2019) and, in some cases, new challenger parties have been found to exploit a new ‘universalism-particularism’ dimension in political conflict (Häusermann and Kriesi 2015). Where it has become politically relevant, this additional dimension of conflict has added further complexity to political competition in European democracies.