WASHINGTON — A Donald Trump rally in Virginia was repeatedly disrupted on Monday by protesters, including some from the Black Lives Matter movement, in a stark display of the divisions the Republican front-runner’s presidential campaign has long been accused of encouraging.

A Time magazine photographer trying to document the exit of dozens of black protesters from the rally in southwestern Radford, Virginia, was grabbed by the neck and shoved to the ground by a Secret Service agent.

The Trump rally took place on the eve of Super Tuesday, the biggest voting day in the race to pick the 2016 presidential nominees for the November election. Thirteen states including Virginia are holding contests on Tuesday and opinion polls show Trump is likely to consolidate his status as favorite to win the Republican nomination.

Hecklers disrupted the rally on a day when the New York billionaire fended off criticism that he had not clearly condemned white supremacist support during an interview on CNN on Sunday.

As black protesters were escorted from the rally, the crowd around them began to chant, “All lives matter.”

Black Lives Matter is a civil rights movement that sprung from police shootings of black Americans in recent years.

On Monday, the protesters disrupted Trump’s remarks several times for long stretches, prompting him to shout to security guards several times, “Get them out, please, get them out.”

Trump appeared to relish the discord, saying after the turmoil in the crowd that his rallies were more exciting than those of the other candidates: “But it is fun, and exciting.”

Time photographer Chris Morris was on the fringe of an enclosed media section when he was seized by an agent from the Secret Service, which has the job of protecting the president and some White House candidates.

“I stepped 18 inches out of the (press) pen and then he grabbed me by the neck and started choking me and then he slammed me to the ground,” Morris told CNN at the scene.

The Trump campaign said it was not aware of the details of the incident and directed inquiries to local law enforcement.

Secret Service spokesman Robert Hoback said the agency was aware of the incident involving one of its employees but it still working to “determine the exact circumstances that led up to this incident.”

Earlier Monday, Trump’s rivals slammed him for equivocating on white supremacist support when he was asked repeatedly on CNN if he would condemn the Klan and disavow support from white supremacists, including David Duke, a former Klan grand wizard from Louisiana.

Trump said that he had been hampered by a faulty earpiece during the CNN interview.

Duke on Monday denied that he had endorsed Trump. But he said he planned to vote for him and had advised his friends to do so too because of the candidate’s views on immigration and world peace.

It was unclear whether Trump would be damaged by support from white supremacists. He has risen in opinion polls and won three of four early nominating contests while proposing a temporary ban on Muslims entering the country, calling Mexican immigrants criminals and insulting women.

His rivals for the Republican nomination, Sens. Ted Cruz of Texas and Marco Rubio of Florida, urged him to ask the New York Times to release a recording of his recent interview with its editorial board, following a report he told it he was not serious about his immigration proposals.

On the Democratic side, front-runner Hillary Clinton alluded to the country’s divisions Monday after a landslide victory Saturday in South Carolina’s primary shifted her attention from party rival Bernie Sanders to the candidate she may end up facing in November.

“I don’t think America ever stopped being great,” she told supporters in Massachusetts, adding a twist to Trump’s “Make America Great Again” slogan. “What we need to do now is make America whole.”

Also Monday, Sanders took a jab at Clinton for the “substantial sums” a super-PAC supporting her has collected from corporate interests and reiterated his plans to stay in the race until voters in all 50 states have spoken.

“Tomorrow, all over the country our campaign is taking on the political establishment,” the Vermont senator said. “We’re taking on governors and senators and mayors who know how to get out the vote. They do that very well.

“We will do well tomorrow if there is a large voter turnout, if working people, if young people, if people in many cases who have given up on the political process want to stand up and fight back and they come out to vote tomorrow,” Sanders said.

Asked about previous statements about staying in the race through the Democratic convention, Sanders noted that only four states have weighed in to this point.

“At the end of tomorrow, I think 15 states will have spoken,” Sanders said. “Last I heard, we have a lot more than 15 states in the United States of America, and I think it is more than appropriate to give all of those states and the people in those states a chance to vote for the candidate of their choice.”