In tutelary democracies, two inimical visions of government – guardianship and democracy – co-exist in a hybrid arrangement. Drawing on insights from the presidentialism versus parliamentarism debate, this paper examines the dynamics of competition between the guardians and popular challengers to their authority in two tutelary democracies: The Islamic Republic of Iran, which features a presidential arrangement under the guardianship of a supreme clerical authority, and Turkey, where until recently parliamentary democracy was constrained by military tutelage. I argue that the executive branch of government lies at the heart of the foundational tension of tutelary democracies: whereas guardians strive to limit the political authority of elected officials by dividing executive power into competing institutions and reserving exclusive prerogatives for themselves, elected challengers strive to push back by popularising and personalising – i.e. “presidentialising” – the executive office. However, as tracing the institutional evolution of the two regimes demonstrates, institutional engineering by the guardians does not always produce intended results, and the victory of popular contenders over tutelary actors does not guarantee consolidation of liberal democracy.