In this Oct. 15, 2019, photo, Donald Trump Jr. speaks to supporters of his father, President Donald Trump, during a panel discussion in San Antonio. Trump Jr.'s appearance Sunday at the University of California at Los Angeles to talk about his new book on liberals and free speech was marked by an argument between him and the audience over why he would not take questions, the Guardian newspaper reported. Credit: Eric Gay | AP

Donald Trump Jr. and Trump campaign senior adviser Kimberly Guilfoyle came prepared with snappy rejoinders for liberal protesters who might taunt them on Sunday at the University of California at Los Angeles, where they promoted Trump Jr.’s new book, “Triggered: How the Left Thrives on Hate and Wants to Silence Us.”

But when unruly heckling drowned out the couple’s answers, leading the pair to walk offstage, it wasn’t leftists who cut the event short. Instead, the rebukes came from a crowd of young people who rank among the most ardent and extreme supporters of President Donald Trump.

As first reported by the Guardian, a number of conservatives — some in telltale “Make America Great Again” caps and pro-Trump attire — began to shout at the president’s son and political adviser 20 minutes into an event moderated by Turning Point USA founder Charlie Kirk, after learning a question-and-answer session had been canceled.

Video from the event showed a chant that started out as “U-S-A! U-S-A!” turning quickly into angry cries of “Q-and-A! Q-and-A!” Minutes later, Trump Jr. and Guilfoyle stormed off the stage.

The chaotic scene contradicted Trump Jr.’s central thesis that liberals have grown so intolerant of dissenting voices, conservative politicians can no longer engage in civil discourse. It also exposed an increasingly hostile fissure between conservative student groups such as Turning Point USA and a hard-right faction of young Trump devotees who have flocked to self-professed “American Nationalist” Nicholas Fuentes and his “America First” movement.

Turning Point USA and a spokesman for Trump Jr. did not immediately return requests for comment early Monday morning.

At the Sunday event, Trump appeared to think the first shouts of dissent had come from left-leaning counterprotesters.

“Name a time when conservatives have disrupted even the furthest leftist on a college campus,” he said to the crowd. “It doesn’t happen that way. We’re willing to listen.”

A member of the audience interrupted with a shout: “Then open the Q&A!”

“See what I mean?” Trump answered. “And that is the problem. And the reason oftentimes it doesn’t make sense to do the Q&A is not because we’re not willing to talk about the questions, cause we do. No. It’s because people hijack it with nonsense looking to go for some sort of sound bite. You have people spreading nonsense, spreading hate, trying to take over the room.”

The roar of the crowd shouting “Q&A!” grew louder, threatening to completely overpower Trump and Guilfoyle inside Moore Hall on UCLA’s campus.

Guilfoyle shouted back at the young men, insulting their appearances and manners.

“No, it’s because you’re not making your parents proud by being rude and disruptive and discourteous,” she responded. “We are happy to answer a question. Respect the people around you so that they can hear.”

When the crowd continued to demand a chance to ask questions, Guilfoyle snapped, “Let me tell you something, I bet you engage and go on online dating because you’re impressing no one here to get a date in person.”

That response only inflamed the protesters, whose loud chants soon led the pair to leave the stage.

Fuentes, 21, appeared to take credit for the protests on Sunday evening, tweeting that he and his followers don’t disagree with Trump. Instead, he said, their complaint was with Turning Point USA. On Sunday, he shared dozens of tweets celebrating the event’s shutdown and denigrating Turning Point USA.

“Our problem is not with [Trump Jr.] who is a patriot — We are supporters of his father!” he tweeted. “Our problem is with Charlie Kirk’s TPUSA organization that SHUTS DOWN and SMEARS socially conservative Christians and supporters of President Trump’s agenda. We are AMERICA FIRST!”

The host of an ultraconservative podcast and YouTube show called “America First,” Fuentes has appeared on YouTube with bloggers who advocate for a white ethnostate. He has used slurs and promoted anti-Semitism in his broadcasts, which has put him at odds with Daily Wire editor Ben Shapiro. Fuentes marched in Charlottesville with white supremacists during the deadly Unite the Right rally in 2017, the Boston Globe reported.

For weeks, Fuentes has been railing against Turning Point USA, which once invited him to speak at Iowa State University, and the more mainstream wing of the pro-Trump movement. On Nov. 4, he directed his fans to show up to Turning Point USA events and heckle speakers during question-and-answer segments. His fans have harassed Kirk at several recent Turning Point USA events on college campuses.

“They’re literally campaigning for Trump and they have to discriminate against his voters,” Fuentes said in a YouTube video last week. “We’re going to make it known that that’s exactly what it is: a controlled conversation. People do not go to a ‘free speech’ thing and get dragged to the back of the line, kicked out, because they don’t fit the profile of what a questioner is supposed to look like.”

Two men at Sunday’s event, identified as Joe and Orion Miles, told the Guardian they believe the pro-Trump movement has been spoiled by “fake conservatism” and that deep state operatives harm the president’s agenda. They claimed victory on Sunday for shutting down the event.

“It was an absolute disaster for them,” the pair told the newspaper. “We wanted to ask questions about immigration and about Christianity, but they didn’t want to face those questions.”

Meanwhile, the liberal protesters Trump might have expected to interrupt his book talk showed up in smaller numbers. About three dozen anti-Trump demonstrators played the drums and held “Trump/Pence Out Now” signs outside. One Trump critic occasionally shouted and booed from the audience inside Moore Hall, leading Kirk, Trump and Guilfoyle to call her “triggered.” Less than a half-hour later, she was drowned out by the far-right agitators.