Donald Trump wants to crack down on 'sanctuary cities'. What does that mean?

On Monday, the US president took another swing at cities that protect immigrants and limit Ice cooperation Since his first day in office, Donald Trump has zeroed in on so-called "sanctuary cities", pledging to withhold federal funding and ensure they are eliminated as part of his administration's massive crackdown on immigrants. On Monday, he took yet another swing, directing his administration to publish a list of state and local jurisdictions that "obstruct the enforcement of federal immigrati...