The watermelon effect: How immigration policies affect migrant political support

Abstract Do immigration policies impact long-term political integration? I argue that the interplay between admission requirements and post-admission rights of migrants is highly consequential in shaping key democratic attitudes of increasingly diverse societies. Migrant selectivity boosts democratic satisfaction and political trust only when combined with inclusive internal regulations, such as high security of status, easier pathways to settlement, and social rights. Analyzing Commonwealth migrants in the UK after WWII through difference-in-differences and interrupted time series models, I find that ‘watermelon regimes’ (strict entry with inclusive post-entry rights) show lasting positive effects. Cross-national analyses with European data support the findings that watermelon regimes outperform free movement and stricter policies. Selection and context mechanisms explain why watermelon regimes enhance migrants’ economic integration, leading to political support. The benefits and costs of adopting watermelon regimes are discussed.