What next after Trump's rally canceled?
A Donald Trump campaign that for months seemed to grow stronger with every controversial statement was put on ice for at least one night by a raucous crowd of Chicago protesters that overwhelmed his planned rally and enraged many of his supporters.
A line that wrapped around the University of Illinois Pavilion for hours before the event was largely peaceful as Trump supporters and detractors stood together without the reports of violence that have plagued his campaign in recent weeks.
But inside the arena was much different.
More than 30 minutes after the Republican presidential front-runner was scheduled to take the stage at 6 p.m., factions clashed through competing chants.
Then, an announcer said Trump had arrived in Chicago, consulted with law enforcement officials and decided to cancel the rally because of safety concerns.
At that, the crowd erupted in bedlam with spectators flooding the arena floor. Clashes appeared to be mostly verbal, but some people were videorecorded throwing punches and shoving.
"Are you guys satisfied?" one red-faced Trump supporter repeatedly yelled, jabbing his finger at TV news crews on risers.
Emily Jahn, of Grayslake, said she and her mother attended the event not to show support or opposition but just to see what happened.
"He wouldn't have put it at a college campus in the middle of Chicago unless he wanted people to get mad," she said. "I think it's what he wanted, to get attention."
What happens now for Trump and his primary race against Texas Sen. Ted Cruz, Florida Sen. Marco Rubio and Ohio Gov. John Kasich could play out over the coming days. Illinois' primary is Tuesday.
In an interview with MSNBC anchor Chris Matthews, Trump was defensive and argued that anger boiling over at his rallies had been building for years and was not spurred by his campaign alone.
"We have a very divided country," Trump said. "We have a country that's so divided that maybe even you don't understand it. I've never seen anything like it."
Cruz, speaking Friday at the Northwest Suburban Republicans' Lincoln Day Dinner in Rolling Meadows, called the clash at UIC "a sad day" but suggested Trump's rhetoric was partly responsible. "I hope going forward for a respectful, substantive, issue-based discussion," Cruz said.
Trump and all of the Republican candidates initially had been invited to the Rolling Meadows dinner, and after his Chicago rally was shut down Trump offered to make an appearance but was "politely declined," a source said.
Trump has run a campaign aimed at disrupting the political establishment, and many of the protesters Friday night were backers of the race's other anti-establishment candidate, Vermont Sen. Bernie Sanders.
Hundreds of protesters inside the UIC Pavilion chanted "Bernie, Bernie," who also had a rally Friday night in the suburbs.
Trump's campaign issued a statement saying Trump had arrived in Chicago and "after meeting with law enforcement has determined that for the safety of all of the tens of thousands of people that have gathered in and around the arena, tonight's rally will be postponed to another date. Thank you very much for your attendance and please go in peace."
The Chicago Police Department said it was informed shortly before 6:30 p.m. that the Trump campaign had canceled the event. Police were not consulted before the decision was made, according to spokesman Anthony Guglielmi.
Kevin Booker, chief of the University of Illinois at Chicago police, said no one was injured or arrested as the arena was emptied.
After the rally, protesters took to the streets where they were lined up behind barricades and faced by many police officers, including more than a dozen officers on horses.
"Who won? We won," hundreds of protesters chanted.
Barry Rush, a medical student at the University of Illinois at Chicago, says he disagrees with Trump's rhetoric and hopes other cities will follow Chicago.
"I think that other cities will follow and will show him that we're not going to stand for this kind of junk," Rush said.
Thirty-two people were arrested at a St. Louis rally earlier Friday, and reports of violence at recent Trump events dogged the candidate in Thursday night's debate.
"People come with tremendous passion and love for the country," Trump said at Thursday's debate. "When they see what's going on in this country, they have anger that's unbelievable."
A white Trump supporter was charged with assault Thursday after video showed him hitting a black man being escorted out of the venue by sheriff's deputies at a campaign rally Wednesday in North Carolina.
Trump told MSNBC in a telephone interview after the Chicago cancellation: "I just don't want to see people hurt. We can come back and do it another time."
But with the election four days away, it was unclear what he meant.
Sanders, who addressed a rally of his own Friday in Summit, expressed concern over the incident.
"I hope that we are not in a moment in American history where people are going to be intimidated and roughed up and frightened about going to a political rally ... . I hope Mr. Trump speaks out forcefully and tells his supporters that that is not what the American political process is about."
• The Washington Post contributed to this article.