The rising prominence of populist movements and new political parties around the world in recent years has roiled democratic countries. Some of the more dramatic examples—Brexit, the election of Donald Trump in the United States, and the growing electoral viability of anti-immigrant parties in many countries—are threatening to shift the global political landscape and with it longstanding social and political cleavages in democratic polities. The possibility that the class divide has flipped on its head, with growing numbers of educated middle-class citizens favoring new or traditional left parties and the new right parties attracting significant blocs of poor and working- and lower-middle class citizens has reanimated interest in the question of how socioeconomic divisions shape citizens’ policy preferences and social attitudes. A new generation of scholarship is struggling to analyze the diverse ways in which the social class location of individuals shapes their dispositions and preferences, and whether and how they have shifted over time. Attitudes toward topics such as globalization, immigration, the environment, and “new” social issues of identity and rights are among the many challenges to the traditional left–right continuum in the polities of rich democratic countries.