Immigration law, the mayors said, is a federal responsibility, and the attempt to put that responsibility on local law enforcement makes communities distrust the police and others they may need to call for help. Trump’s crackdown, the mayors said, has terrified immigrants, many of them in the U.S. legally.

Denver Mayor Mike Johnston testified on Capitol Hill about the so-called "sanctuary city" policies on Wednesday morning. He was invited by the Republican-led U.S. House Committee on Oversight and Government Reform,