UPDATE: Trump phoned in to "On the Record" with Greta Van Susteren on Fox News Friday evening to explain his decision for canceling the rally. Trump said that after meeting with various law enforcement agencies he made the decision not to do the rally, but to postpone it.
"I just don’t want to see people get hurt, any people, on either side. You know we have such a divided country now. I’ve been witnessing it in so many different forms, it’s just something that has to be straightened out. … There’s a lot of anger out there … because we’re losing our jobs, we’re losing our manufacturing, we’re losing so much. …"
He also said he believed "this is a demonstration against economic conditions."
UPDATE: The Trump campaign has issued a statement regarding Friday night's scheduled rally in Chicago:
Donald Trump postponed a rally in Chicago Friday evening due to safety concerns after protesters swarmed into the arena where it was supposed to be held.
The announcement that Trump would postpone the rally for another day led the crowd inside the University of Illinois at Chicago Pavilion to break out into raucous cheers.
Meanwhile, supporters of the candidate broke out into chants of "We want Trump! We want Trump!"
There was no sign of Trump inside the arena on the college campus, where dozens of UIC faculty and staff had petitioned university administrators to cancel the rally. They cited concerns it would create a "hostile and physically dangerous environment" for students.
Craziness in lower bowl of UIC Pavilion. People looking for a fight. pic.twitter.com/VANBa0O1rs— Kevin Pang (@pang) March 12, 2016