This article offers a systematic, longitudinal and cross-national assessment of the constraint democratic institutions place on domestic political violence. It formulates two structural equation models which allows for the examination of the relative contribution of formal institutions and political culture as sources of constraint on political violence. Institutionalized opportunities for democratic participation significantly reduce political violence; however, these institutions only realize their full potential when embedded within a deliberative political culture. This article suggests that when oppositional groups view democratic participation as meaningful, and state elites engage with their claims, these groups are inclined to behave as radical democrats rather than violent extremists.