In recent weeks, authorities have arrested people in at least three states and accused them of acting like they’re carrying out the work of U.S. Immigration and Customs Enforcement.

The Justice Department accused the Democratic strongholds of unlawfully interfering with Trump's crackdown and seeking a court order blocking so-called sanctuary laws.

President Donald Trump’s administration went to court Thursday to challenge sanctuary policies in the state of Illinois, Cook County and the city of Chicago that limit the powers of state and local police to assist federal law enforcement on immigration-related matters.