Radical-right behavior is increasing across Western democracies, often very quickly. Previous research has shown, however, that political attitudes and preferences do not change as quickly. Vicente Valentim argues that the role of social norms as drivers of political behavior is crucial for understanding these patterns. Building on a norms-based theory of political supply and demand, he argues that growing radical-right behavior is driven by individuals who already had radical-right views, but who did not act on those views because they thought that they were socially unacceptable. If these voters do not express their preferences, politicians can underestimate how much latent support there is for radical-right policy. This leaves the radical right with less skilled leaders, who are unable to mobilize even radical-right voters to support them. However, if politicians realize that there is more private support for radical-right policy than is typically observable, they have an incentive to run for politics with a radical-right platform and to mobilize silent radical-right views. Their electoral success, in turn, leads to radical-right individuals becoming more comfortable in displaying their views, and impels more politicians to join the radical right. The book's argument makes us rethink how political preferences translate into behavior, shows how social norms affect the interaction of political supply and demand, and highlights how a political culture that promotes inclusion can be eroded. Oxford Studies in Democratization is a series for scholars and students of comparative politics and related disciplines. Volumes concentrate on the comparative study of the democratization process that accompanied the decline and termination of the cold war. The geographical focus of the series is primarily Latin America, the Caribbean, Southern and Eastern Europe, and relevant experiences in Africa and Asia. The series editor is Laurence Whitehead, Senior Research Fellow, Nuffield College, University of Oxford.