Sanctuary ordinances or policies that constrain local authorities from assisting in federal immigration enforcement do not receive the same political and media attention as anti-immigrant laws enacted by states and local governments. In the political struggle over the rights of undocumented immigrants in the United States, the greater media and political focus on anti-immigrant measures, such as Arizona’s S.B. 1070 and similar policies in cities like Hazleton, Pennsylvania, and Farmers Branch, Texas, is understandable.

With much less fanfare, the legality of sanctuary policies also has been challenged. In this article I review the case law that specifically has involved the constitutionality of sanctuary policies and the relevant principles of preemption and states’ rights. That process necessarily forces some comparison with the legal challenges over anti-immigrant local and state laws. In my view, while the principles of federalism represented in the Supreme Court’s approach to the Tenth Amendment and preemption drive a stake in the heart of subfederal anti-immigrant laws, those same principles guide us to the conclusion that sanctuary policies are on safe footing.

Understanding why sanctuary policies are constitutional is important to the raging debate over immigration. Seemingly on a daily basis, anti-immigrant measures are proposed or enacted by state and local governments. In contrast, some jurisdictions that regard gaining the trust of immigrant communities as a necessity for public safety or who view themselves as immigrant friendly choose an approach that de-emphasizes the immigration status of those encountered in the course of police work. Additionally, the proliferation of litigation challenging the constitutionality of anti-immigrant ordinances raises the question of whether one set of subfederal immigration-related approaches (sanctuary policies) can be constitutional, while a different set (anti-immigrant legislation) is not. To put it bluntly, can those in the immigrant rights community that promote sanctuary ordinances and attack anti-immigrant proposals have it both ways constitutionally?

I conclude that in the immigration field, the concept of preemption is an appropriate check on overzealous subfederal enforcement efforts that directly affect immigration regulation, while the Tenth Amendment is a check on federal intrusion on a local jurisdiction’s attempt to be more protective of individual rights when the locality has a legitimate nonimmigration-related purpose, such as public safety.

The discussion on the legality of sanctuary policies will reveal that the reserved police powers and local economic decisions under principles of federalism play a major part in the analysis. For that reason, a deeper understanding of the rationale for sanctuary policies is critical. We will find that in jurisdictions with sanctuary policies, local policy makers and law enforcement officials have made thoughtful and deliberate public safety decisions, taking great pains to do the right thing for the entire community. Those decisions are critical to principles of inclusion in our ever-growing diverse communities. For that reason, the sanctuary framework is good public policy—especially in contrast to the anti-immigrant examples of Arizona’s S.B. 1070 or Hazleton, Pennsylvania.