This chapter examines the role of mass beliefs and value change in democratization processes. Building on one of the central assumptions of political culture theory—the congruence thesis—it argues that mass beliefs are of critical importance for a country’s chances to become and remain democratic. Mass beliefs determine whether a political system is accepted as legitimate or not, which has a major impact on a regime’s likelihood of surviving. The chapter first considers how the role of mass beliefs in democratization is addressed in the literature before discussing mass demands for democracy vs popular preferences for democracy. It then discusses regime legitimacy and its relation to economic performance and asks whether emancipative values are caused by democracy. It also explains changes in many countries’ level of democracy and concludes with an analysis of the influence of religion on democratization.