has denounced the protestors – whose presence  amid safety concerns – as "thugs" who "have totally energized America."  after the cancellation "that I hope that my tone is not that of causing violence."  But the Republican presidential front-runner, 69, said that he does not regret his previous public statements about violence toward protestors, saying that he has witnessed moments where protestors at his events themselves turned violent (which Lemon rebuked, citing CNN reporters who have followed the Trump campaign).  "I don't regret it at all. Some of these protestors were violent," Trump  . "They were swinging, they were hitting people and they were really doing damage and, frankly, the crowd turned on them or the police turned on them. In most cases it was the police."  The rally, to be held Friday night at the University of Illinois at Chicago, was postponed following safety concerns, the Trump campaign said, as hundreds of protestors were ticketed for the public event and began demonstrating before it had even started.  "Mr. Trump just 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," the Trump campaign said in a statement, according to CNN. "Thank you very much for your attendance and please go in peace."  Tensions flared following the cancellation, inside and around the space, apparently including physical altercations, according to photos and video from the event.  Five people were arrested and two officers injured, police said, according to CNN. It is not clear if those arrested were protesters or Trump supporters.  Taking to Twitter in the hours after the Chicago cancellation, Trump wrote, "The organized group of people, many of them thugs, who shut down our First Amendment rights in Chicago, have totally energized America!"  The organized group of people, many of them thugs, who shut down our First Amendment rights in Chicago, have totally energized America!  Son Donald Trump Jr. echoed that argument  : "Liberals love the first amendment until you say something they don't agree with."  (That invocation of the Constitution, on murky grounds,  about the limits of "free speech" between private groups.)  This is not the first Trump campaign event  between attendees. And in January,  of a Burlington, Vermont, event and asked that the not be allowed to take their coats with them.  "It's about 10 degrees below zero outside ... You can keep his coat. Tell him we'll send it to him in a couple of weeks," Trump told security.  Trump's fellow presidential candidates were swift with their thoughts on the night's events.  : "A campaign bears responsibility for creating an environment when the candidate urges supporters to engage in physical violence."  "America's better than this. We don't have to tear each other apart instead we can work together," Cruz  , Gov. John Kasich said, in part, "Tonight the seeds of division that Donald Trump has been sowing this whole campaign finally bore fruit, and it was ugly ... I urge people [on all sides] to resist that temptation and rise to a higher level."  : "Presidents can't just say whatever they want. There are consequences to the words of a president. There are consequences to the words of a presidential candidate as well, and you have a candidate in Donald Trump who clearly has used language that appeals to anger and in some instances has actually said to the crowd, 'Let's beat this person up.' "  Rubio added, "I would point out, there isn't violence at my events" – or any of the events of the other candidates, Democrat of Republican, he said.  did not directly mention Trump or the event, instead focusing on how to overcome "divisive rhetoric" that fuels every side into conflict.  "The divisive rhetoric we are seeing should be of grave concern to us all," she said. "We all have our differences, and we know many people across the country feel angry. We need to address that anger together. All of us, no matter what party we belong to or what views we hold, should not only say loudly and clearly that violence has no place in our politics, we should use our words and deeds to bring Americans together."  Clinton went on to cite the example of the families of the Charleston shooting victims last year, killed, authorities have said,  "The families of those victims came together and melted hearts in the statehouse and the confederate flag came down," Clinton said in her statement. "That should be the model we strive for to overcome painful divisions in our country."  with the caption, "We will continue to bring people together. We will not allow the Donald Trumps of the world to divide us up."
Within hours, every other presidential nominee had responded to the Friday night events, which apparently included physical altercations between attendees