What drives Islamists’ democratic commitments? Does modernization turn them into committed democrats? Or do institutions rein in their authoritarian tendencies through political socialization and democratic habituation? This chapter critically reviews three theories that define the scholarly debate surrounding these questions while providing a historical and political context to all three cases. It first explores the history of modernization in Turkey, Egypt, and Tunisia and discusses the role of socioeconomic factors on the democratization of Islamist parties. Then it discusses the impact of institutions on party behavior and ideology, specifically the inclusion–moderation thesis to test its claims against the evidence we now have with the rise of Islamist parties to power. This survey reveals the limits of the institutional and ideational effects of inclusion. The final section turns to the strategic calculations of Islamist actors to discuss the role played by external factors, including regional and international developments. The central claim of the chapter is that existing accounts offer only a partial explanation failing to address diversity of perspectives and internal conflicts within Islamist parties.

This chapter reviews the existing literature on religious party change. The scholarly literature offers three major explanations for the divergence we observe in Catholic and Islamist parties’ trajectories and for why religious parties change, or moderate: religious, political, and institutional explanations. Despite major contributions to our understanding of religious parties, the literatures on Catholic and Islamist parties grew virtually independent of each other, focusing on entirely different sets of questions or factors that explain change in these parties. Building on the existing literature, this chapter lays out the theory developed in this book to explain religious party change. First, an overview of the political economic approach to the study of religion is presented; next, the chapter outlines the effect of institutions on political behavior, and in particular how religious institutions affect political behavior and religious parties. Finally, the major actors in the theory are analyzed before concluding with a comparative assessment of how Islamist and Catholic parties fit into the theory.