ABSTRACT As artificial intelligence (AI) technologies become ubiquitous, research on their implications for democratization has blossomed. Will AI empower citizens and strengthen democracy or fuel the rise of autocracy? This special issue brings together diverse theoretical, conceptual, and empirical contributions to offer a synoptic perspective on this question across political contexts. In this introduction, we argue that the most significant socio-technical novelty pertaining to AI - the possibility for automated hyper-personalization - catalyses four structural changes that capture the complex relationship between AI, democratization, and autocratization. First, technology corporations have emerged as a new quasi-governing class that holds political power without democratic legitimacy. Second, automated hyper-personalization has transformed the citizen-state relationship by fostering hyper-technocracy and paternalism in democracies, and enhancing regimes' repertoires for controlling citizens in autocracies. Third, AI is changing the environment in which citizens exercise their political rights, exacerbating political polarization, societal fragmentation, and apathy. Finally, at the international level, AI has created new arenas for competition between democratic and authoritarian states, engendering a struggle for both technological capabilities and the values and norms that will govern them. The articles in this special issue explore these dynamics from micro impacts to structural changes in state behaviour and international relations.