The Introduction sets the framework for the analysis and introduces the central research question of The Politics of Religious Party Change: when and why do religious parties become less anti-system? This chapter explains the significance of the question, discussing the rising prominence of religious parties globally and the need to better understand the dynamics of change in these parties. Likewise, the Introduction details the methodology used in this book and the six empirical cases: The Egyptian Muslim Brotherhood, Tunisian Ennahdha, Turkish AKP, German Center Party, Italian PPI, and Belgian Catholic Party.

The Politics of Religious Party Change addresses the timely question of ideological change and secularization of religious political parties and asks, when and why do religious parties become less anti-system? In a comparative analysis, this book traces the striking similarities in the historical origins of Islamist and Catholic parties in the Middle East and Western Europe, chronicles their conflicts with existing religious authorities, and analyzes the subsequently divergent trajectories of Islamist and Catholic parties. Religious parties are embedded in distinct religious institutional structures that shape their actions as they chart their paths in electoral politics. Counterintuitively, the book finds that centralized and hierarchical religious authority structures – such as the Vatican – incentivize religious parties to move in a more pro-system, secular, and democratic direction. By contrast, less centralized religious authority structures such as in Sunni Islam create a more permissive environment for religious parties to operate as anti-system parties hostile to democracy and secularism.