As far as immigration theory is concerned, the attempt to reconcile concern for all persons with the reality of state boundaries and exclusionary policies has proved difficult within the limits of normative liberal political philosophy. However, the realpolitik of migration in today's environment forces a major paradigm shift. We must move beyond standard debates between those who argue for more open borders and those who argue for more closed borders. This book aims to show that a realistic utopia of political theory of immigration is possible, but argues that to do so we must focus on expanding the boundaries of what are familiar normative positions in political theory. Theorists must better inform themselves of the concrete challenges facing migration policies: statelessness, brain drain, migrant rights, asylum policies, migrant detention practices, climate refugees, etc. We must ask: what is the best we can and ought to wish for in the face of these difficult migration challenges.