This chapter sums up the book’s key theoretical claims and empirical findings and then explores the extension of its argument beyond the cases examined in the empirical chapters. It first applies the argument to additional migration-related policy areas, including asylum, refugee resettlement, migration control, immigrant integration, and citizenship policy. The chapter then ventures beyond the national level of policy making by using the insulation framework to shed light on the logic of immigration policy making in the European Union, followed by subnational policy making. The chapter concludes with an appraisal of the future politics of immigration policy.