When and how do domestic politics influence a state's nuclear choices? Recent scholarship on nuclear security develops many domestic-political explanations for different nuclear decisions. These explanations are partly the result of two welcome trends: first, scholars have expanded the nuclear timeline, examining state behavior before and after nuclear proliferation; and second, scholars have moved beyond blunt distinctions between democracies and autocracies to more fine-grained understandings of domestic constraints. But without linkages between them, new domestic-political findings could be dismissed as a laundry list of factors that do not explain significant variation in nuclear decisions. This review essay assesses recent research on domestic politics and nuclear security, and develops a framework that illuminates when and how domestic-political mechanisms are likely to affect nuclear choices. In contrast to most previous domestic arguments, many of the newer domestic-political mechanisms posited in the literature are in some way top-down; that is, they show leaders deliberately maintaining or loosening control over nuclear choices. Two dimensions govern the extent and nature of domestic-political influence on nuclear choices: the degree of threat uncertainty and the costs and benefits to leaders of expanding the circle of domestic actors involved in a nuclear decision. The framework developed in this review essay helps make sense of several cases explored in the recent nuclear security literature. It also has implications for understanding when and how domestic-political arguments might diverge from the predictions of security-based analyses.