Over the last half century, democratic political institutions have emerged as the principal means for reducing state coercive power. To advance this approach to domestic peace, individuals have requested, lobbied, boycotted, protested, revolted, invaded, and occupied – on hundreds of occasions; they have spent billions of dollars on democratic preparation and promotion (for example, voter awareness campaigns); and they have (re)designed constitutions and held elections at local as well as national levels, involving millions of people.

The work of these activists and policymakers notwithstanding, the question of the efficacy of democratic institutions remains open. Are democratic institutions, the best of an imperfect set of choices as Dahl and others argue? Does democracy pacify state repression? Over the past thirty-five years, research in international relations and comparative politics has led us to believe that, yes, democracy does reduce repressive behavior. Unfortunately, however, it is also clear from this work that the conclusion is potentially misleading because three limitations plague the literature. It is not clear whether all types of repression are equally susceptible to the influence of democratic political institutions (the problem of repressive variation). It is not clear whether all aspects of democracy are equally capable of reducing repressive behavior (the problem of democratic variation). And it is not clear whether different aspects of political democracy are equally capable of reducing repression in circumstances of varying types of political threat (the problem of conflictual variation). These are the issues that motivated the current research.