The fate of regimes after the Arab Spring has prompted scholars to reconsider how authoritarian institutions affect mass protest. Why did Mubarak fall, but not King Mohammed VI of Morocco? Are the paths to regime change different in monarchies? This article argues that monarchies have a unique institutional feature that other authoritarian regimes lack: they can democratize without destabilizing the leadership by transitioning to a democratic constitutional monarchy. The promise of constitutional monarchy affects protestor demands and weakens mass mobilization for regime change. Kings do not survive protest waves because they are smarter, more legitimate, or more likely to institute meaningful reforms. Nor are they invulnerable; monarchies can and do crumble. But monarchs are less likely than other authoritarian rulers to be overthrown via mass protest. This article provides a theory of the differences between monarchies and other authoritarian regimes, drawing on cross-national studies and a case study of Morocco.