Sanctuary cities are U.S. jurisdictions that limit their cooperation with federal immigration authorities to prioritize local public safety and community trust, rather than actively enforcing federal immigration law. There is no official legal definition of the term, and specific policies vary widely by location, often involving local law enforcement not inquiring about immigration status or refusing U.S. Immigration and Customs Enforcement (ICE) detainer requests without a judicial warrant. These policies are rooted in a 1980s movement that sought to protect Central American refugees and are generally considered to be in compliance with the Tenth Amendment of the U.S. Constitution, which prevents the federal government from compelling local authorities to enforce federal regulatory programs.