This dissertation examines how polities are being transformed by, and are responding to, increased global migration focusing on the immigration control policies of advanced industrialized democracies. It argues that increased global migration has reaffirmed and entrenched the exclusionary prerogatives of immigration control, meaning the sovereign right of states to "keep out the other." This has led to a tightening of citizenship and a narrowing of the boundaries of political and societal inclusion. I provide evidence of this using a mixed methods multi-level analysis that focuses on the nexus between emergent human rights norms, global migratory trends, and state policies directed towards irregular (i.e., undocumented/illegal) migrants. In weaving together this nexus, this dissertation bridges central debates about globalization and human rights in international relations with new research on immigration control in comparative politics.

At the international level, in an analysis of 160 countries from 1990 to 2008, I find that human rights treaties that require states to extend fundamental rights to noncitizens are among the most poorly ratified treaties. But more than that, as immigration into a country increases even liberal democracies become less likely to ratify, as doing so may encourage more immigration. I then move to a comparative analysis of immigration control across Western democracies, focusing on deportation and immigration detention. This dissertation is among the first to analyze contemporary trends in these critical indicators of immigration control across countries and over time. I find that economic and migration factors only partially explain trends in deportation and detention. Rather, it is the legislative representation of the far right that significantly increases the restrictiveness of immigration control. In examining how the far right "matters," I find that the political opportunities created by electoral rules explain the impact of the far right more so than public demand for more restrictive policies. Moreover, while there is no clear evidence that more immigration control means less immigration, there is some evidence to suggest that it does result in less asylum inflows. Lastly, I examine the microfoundations of immigration control using in-depth interviews with immigration enforcement officials and irregular migrants. I introduce a theory of selective immigration control that views immigration enforcement as a suboptimal outcome that is constrained by institutional and individual-level factors that make certain categories of migrants more or less deportable. As a result, those who are "easiest" to remove become disproportionately the targets of immigration enforcement; these are often the most vulnerable migrants.