Research on the politics of migration has so far largely produced context-bound analyses that tie specific migration policies to specific political regimes. This introduction charts existing migration research, including its gaps and biases, and introduces new avenues for empirically grounded theory-building. We draw upon the rich collection of empirical cases assembled in this volume to demonstrate that political regimes – be they liberal or illiberal, democratic or authoritarian – do not strictly and mechanically determine migration politics. Instead, we argue that migration politics and political regimes co-produce each other. Studies of migration politics in Argentina, Tunisia, Japan and South Korea, the United States and Australia, the Philippines, China, and Saudi Arabia showcase the imbrication of migration politics with broader dynamics of regime change, state formation and nation-state ideology, and dissect the role of civil society, legal actors, employers, and international norms across democratic and un-democratic contexts. They reveal unexpected similarities in migration policies in different political regimes at a time when states across the globe are increasingly adopting illiberal practices and policies. Ultimately, we suggest that, beyond contextual variations, migration politics offers an ideal vantage point for understanding state transformations and political changes around the world.