Who’s a part(y) of this family? Only noneconomic niche parties are still responsive to partisans

Foundational manuscripts examined whether niche parties and mainstream parties differed in their party-voter linkages. Specifically, they examine “mean electorate” and “partisan electorate” forms of party responsiveness using data from the twentieth century. Importantly, these early studies followed a party family approach and defined all nationalist, communist, and ecological parties as “niche parties”. Using data covering 75 European parties in the period 2006-2019, we show that this foundational difference between niche and mainstream parties is still valid, though not on the same set of party families. Economically-focused mainstream parties continue to respond to the mean electorate rather than their partisans, but so do communist parties, which have previously been classified as niche. We propose an alternative operationalization of niche party families, which include ethno-regional and rural-interest parties and in turn exclude communist parties. With this distinction, we do indeed find that niche parties respond to their partisans on both the general left-right dimension as well as on two issue dimensions. These results also serve to caution future users of the niche party concept to focus on parties whose raison d'etre are noneconomic issues when using a party family approach.