When Is Cultural Diversity a Threat? the Determinants of Mainstream Political Parties' Use of Exclusionary Appeals

In light of the mixed results linking outgroup size to feelings of cultural threat, recent studies argue that this relationship is conditional on national rhetoric by mainstream parties in particular. Yet when will mainstream parties politicize the presence of immigrants as a threat? Focusing on the center-right, I show that existing approaches emphasizing party competition are unable to account for many notable instances of these parties politicizing xenophobia. Using original data on citizenship acquisitions, inflows, and the composition of the foreigner population from six Western European countries – Denmark, France, Germany, the Netherlands, Sweden, and the UK – from 1970 and 2010, I specify when and why the presence of an outgroup will generate incentives to mobilize anti-immigrant feelings into perceptions of threat. In particular, by disaggregating the category “immigrant” minorities into citizens and non-citizens, I show that changes in the relative number of ethnic minorities with citizenship to the foreigner population, or the citizenship ratio, creates incentives for parties to portray immigrants as a threat to the nation, despite differences in institutional, competitive, and economic conditions.