A simple model of party formation supplies microfoundations for Lipset
and Rokkan's classic theory and explains the formation of confessiona
l parties as the contingent and unwanted by-product of strategic choic
es made by the church and conservative political elites under constrai
nts. By mobilizing lay Catholics as Catholics, the church and conserva
tive elites created a new political actor, the confessional party, wit
h its own preferences. This process of party formation has far-reachin
g consequences, and the distinctive and puzzling characteristics of co
ntemporary Christian Democracy can be traced back to it.