Fists fly in Chicago. How will Donald Trump respond?

Only days after a white Donald Trump supporter told a TV crew he relished punching “the big mouth” of a protester in Fayetteville, N.C., the frontrunner GOP candidate cancelled an event Friday in Chicago after skirmishes broke out between anti-Trump protesters and pro-Trump attendees on the floor of a convention center.

The rising tide of violence on the campaign trail suggested that Mr. Trump’s political success is sparking a backlash that threatens to devolve into something new and ugly, where, as the Atlantic’s David Graham noted this week, “there are thousands of people who are deeply angry at the state of the nation, whose anger is being intensified by the speaker on stage.”

The extent to which the campaign can regain order and civility may be largely up to how Trump responds – and whether he cools his own tactic of using disruptive protesters as occasion to ramp up emotions among his supporters. On Saturday, Trump is scheduled to campaign in Dayton and Cleveland, Ohio and finish the day with an event in Kansas City, Mo. 

Before the Chicago event devolved, dozens of people were arrested in St. Louis outside the Peabody Opera, where Trump spoke. A bloodied protester and a bloodied cop emerged from that event as images of an America in turmoil. GOP candidate Sen. Marco Rubio worried that “our republic is fracturing.”

“The volatile convergence of thousands of Trump supporters and protesters … reflected the two extremes of the political landscape — a disaffected right wing and a dissatisfied left wing,” noted the Chicago Tribune after Friday's canceled campaign speech.

Mr. Trump deflected responsibility for the bloody melees and arrests, saying protesters have gotten so aggressive “you can’t even hold a rally anymore.”

But Trump was roundly condemned by his fellow Republicans on Friday night. Texas Sen. Ted Cruz predicted more clashes. Mr. Rubio said Trump should stop talking about calling violence against protesters a “beautiful thing,” as he did in Fayetteville on Wednesday before the protester got punched.

“If you're running for president, you have to understand that that kind of rhetoric from a president – or a major presidential candidate -- has ramifications," Mr. Rubio said.

But the scenes of mayhem in Chicago – the site of the bloody 1968 Democratic Convention and the city that hosted Obama’s 2008 election victory – also underscore just how deeply Trump has tapped into a disaffected population, largely rooted in working and middle-class America, who see interruptions from protesters as a concerted effort to silence Trump – and, by proxy, them.

So far, Trump has called a growing list of troubling incidents at his rallies unfortunate but has not curtailed his populist rhetoric that has singled out Hispanics, Muslims and, now, protesters, who he has called “rough guys” looking for a fight. His response has only earned him more accolades from fans.

At the St. Louis rally, where dozens of people were eventually arrested, Trump said, “They’re allowed to get up and interrupt us horribly and we have to be very, very gentle. They can swing and hit people, but if we hit them back, it’s a terrible, terrible thing, right?” He then ordered the protesters to “go home to mommy” or “get a job,” since they “contribute nothing.”

For their part, police blamed both sides for the escalation in Chicago. “It is unfortunate that parties on both sides allowed their political views to become confrontational,' Chicago Police Interim Superintendent John Escalante said Friday night.

To be sure, the scenes may in the short term help Trump win support, given that he has “taken the politics of anxiety further than Sanders, moving out of an exclusively economic realm to tap into a deeper sense of cultural disenfranchisement among many patriotic Americans," as Stephen Collinson wrote this week on CNN. "Trump and Sanders are appealing to gut-level emotions that amplify political movements, not the wonky details of trade or economic policy."

Trump has racked up a sizable delegate lead by cobbling together a broad voting bloc that includes everyone from Southern evangelicals to Midwestern blue-collar workers. It also includes a larger share of minorities than previous Republican presidential candidates, the Atlantic noted this week. And most Trump supporters have stopped far short of translating Trump's tough rhetoric against reporters, for example, into action. When there have been incidents of journalists getting roughed up, it has involved police or Trump staff, not attendees, the Atlantic reported this week.

But Trump's politically incorrect jabs at fellow Americans has come at the cost of alienating a lot of people, including many minorities, who see Trump as divisive, authoritarian, and unqualified. “Those ugly scenes of last night’s siege in Chicago gave us the clearest picture yet of what American life under a President Donald J. Trump would look like,” wrote the Boston Herald’s Peter Gelzinis. “And it would not be ‘fantastic.’”

Indeed, as Trump faces an Illinois primary this Tuesday, the “continued divisiveness surrounding Trump's campaign also could lead some Republican voters to reconsider whether he could win in the fall, a point that his GOP rivals made in the hours afterward,” the Tribune noted.

After the confrontations subsided Friday, Trump said the tension between his supporters and protesters is evidence that Americans on both the right and left are angry and are looking for ways to salve their discontent.

'There's a lot of anger in the country, and it's very sad to see actually,' he told MSNBC.