The Introduction makes the case for rethinking the politics of immigration across political regimes and for leveraging immigration policy as an analytical lens to explore the inner workings of modern states. I start by sketching the empirical puzzle that motivated the book - the fact that Morocco’s authoritarian regime has enacted a liberal immigration reform, while immigration policies have remained restrictive throughout Tunisia’s democratic transition. I then embed the empirical puzzle in the broader political science debate around the ’regime effect’, which suggests that democracy and autocracy give rise to specific immigration policy processes and outcomes. To pave the way for theory-building, I introduce a three-fold typology of immigration policy processes that systematizes insights into the ‘regime effect’ and distills commonalities and differences in immigration politics across the democracy/autocracy divide. Lastly, I outline the research design and methods adopted to trace immigration policy processes in Morocco and Tunisia and provide an overview of the empirical and theoretical contributions of each chapter.