Immigration: Trump campaigned on a pledge to cut off federal funding to “sanctuary cities” as part of his crackdown on illegal immigration. His chief of staff-designate, Reince Priebus, reiterated the policy in an interview after the election.

These are cities whose police departments aren’t required to check the immigration status of people they stop or arrest or to notify U.S. immigration officials of the status of undocumented persons they release from custody. The roster of sanctuary cities includes Los Angeles, San Francisco, Sacramento and Oakland; an estimated 1 million of the nation’s 11 million immigrants without legal status, many of whom Trump has threatened to deport, live in L.A. County.

Leaders of those cities have pledged to keep protecting immigrants and fight Trump’s proposed cuts in federal funding cuts, which would require congressional action. The stakes are high: Los Angeles receives about $500 million a year in federal funding for such municipal services as port security and homeless shelters. But there are practical as well as moral reasons for cities to steer clear of immigration enforcement. Complicity with immigration agents shatters trust in police in immigrant-rich communities, complicating street-level patrolling. And with undocumented immigrants part of the fabric of diverse communities, rigorous enforcement can have bad economic consequences.