The State of Sanctuary
A sanctuary city limits cooperation with the federal government's effort to enforce immigration law. Sanctuary cities reduce the fear of deportation and possible family break-up among those who are in the country illegally so that such people will be more willing to report crimes, use health and social services, and enroll their kids in school.
These policies prohibit public employees from questioning people about their immigration status and refuses requests by immigration authorities to detain people beyond their release date if they are jailed for breaking local law.