Democracies, and the citizenries that stand at their center, are not natural phenomena; they are made and sustained through politics. Government policies can play a crucial role in this process, shaping the things publics believe and want, the ways citizens view themselves and others, and how they understand and act toward the political system. Yet, while political scientists have said a great deal about how publics influence policies, they know far less about the ways policies influence publics. In this article, we seek to clarify how policies, once enacted, are likely to affect political thought and action in the citizenry. Such effects are hard to locate within the standard framework of approaches to mass behavior, and they are generally ignored by program evaluators and policy analysts. To bridge this gap, we direct attention toward a long and vibrant, but underappreciated, line of inquiry we call the "political tradition" of mass behavior research. Drawing this tradition together with recent work on "policy feedback," we outline a framework for thinking about how policies influence mass politics. The major types of such effects include defining membership; forging political cohesion and group divisions; building or undermining civic capacities; framing policy agendas, problems, and evaluations; and structuring, stimulating, and stalling political participation.