Donald Trump's campaign has canceled a rally in Chicago on Friday night due to security concerns. Trump was already a half hour late when the announcement was made inside an arena at the University of Illinois at Chicago. Thousands of protesters have gathered outside and several hundred inside the arena. "Mr. Trump just arrived in Chicago and after meeting with law enforcement has determined that for the safety of all the tens of thousands of people that have gathered in and around the arena, tonight's rally will be postponed to another date," the campaign said in a statement. Trump called into MSNBC to say "I don't want to see people hurt or worse," two days after he waxed about the "good old days" when protesters would be "carried out on a stretcher."