Sanctuary jurisdiction

A sanctuary jurisdiction is a city, county or state whose laws or policies limit participation by local officials in federal immigration enforcement. There is no legal definition, and policies vary: some bar local police from asking about immigration status, others decline to honor ICE detainers that ask jails to hold someone, and others restrict sharing information or allowing ICE access to jails.

The movement traces to the 1980s church-based sanctuary movement and has grown through local ordinances; California's SB 54 (2017) is a notable state law. Federal law does not require local police to enforce immigration, and the Supreme Court's anti-commandeering decisions, such as Printz v. United States (1997) and Murphy v. NCAA (2018), based on the Tenth Amendment, limit the federal government from compelling them. The federal government can use grants conditions and prosecution of individuals, with mixed success in the courts.

Supporters argue that such policies build trust between immigrant communities and local police, improve public safety and avoid diverting local resources to federal duties. Opponents argue that they shield people who are in the country illegally, including some with criminal records, and release them to the street, and sometimes cite individual crimes; studies of the effect of sanctuary policies on crime generally find no increase. Conflicts over the issue involve the Supremacy Clause.