This article explores how new political actors form and reproduce themselves within societies’ most vulnerable sectors, those marginalized from the state’s authoritative decision-making centers. It explores this question in national settings that characterize much of the contemporary world – that is, settings marked by high levels of political conflict over basic parameters of the political system and hence by significant institutional change. Dominant theories of collective action, such as those rooted in rational choice, political process, and “new social movements” literatures, are based on the experience of relatively stable Western democracies. This article suggests that such theories may not travel well to regions where key background conditions, such as the stability of institutional arrangements that link state and society, do not hold.