What accounts for the virtual absence of new Catholic parties in Latin America over the past four decades? From the late nineteenth to the mid-twentieth centuries, Catholic activists organized a variety of political parties in the region. Yet since the 1970s, despite the dramatic expansion of political opportunities in Catholic-majority countries, Catholicism has played only a marginal role in the formation of new parties. This article develops a novel interpretation of this phenomenon, arguing that changes in the structure of religious communities and church-society relations resulting from the reforms of the Second Vatican Council account for the absence of new Catholic parties. Empirically, it explores this topic through the structured, focused comparison of two periods of social and political upheaval in Venezuela.