Donald Trump 's presidential campaign manager was arrested and charged with misdemeanor battery in Florida on Tuesday in an incident involving a reporter, the latest chapter in a raucous U.S. race marked by threats, insults and physical confrontations.

Police in Jupiter, Florida, charged Corey Lewandowski, 42, with intentionally grabbing and bruising the arm of Michelle Fields, then a reporter for the conservative news outlet Breitbart, when she tried to question Trump at a campaign event on March 8.

Republican front-runner Trump repeatedly defended Lewandowski throughout a day of campaigning in Wisconsin. He also rescinded a previous pledge to support the Republican presidential nominee if it is not him.

"No, not anymore," he said when asked if he would honor his previous pledge.

At a CNN town hall on Tuesday night, Trump said he would remain loyal to his campaign manager and that Lewandowski would remain on the job even though it might be more convenient on behalf of his campaign to "terminate this man, ruin his life, ruin his family ... ruin his whole everything and say: 'You're fired.'"

Trump also questioned Fields' original description of the incident in which she said she was almost yanked to the ground by Lewandowski. He wondered aloud if she had posed a threat to him because she approached him with an ink pen.

"She had a pen in her hand that could’ve been a knife," Trump said.

Police released a video of the incident showing Fields walking alongside Trump and trying to question him. Lewandowski is seen grabbing her arm and pulling her backward. Previous videos of the incident had been obscured by people in the crowd.

At the time, Lewandowski called Fields "delusional" and said he never touched her.

Campaign rallies for Trump, the billionaire businessman who leads the race to become the Republican candidate in the Nov. 8 presidential election, are tumultuous at times and have been marked by occasional clashes between protesters and supporters or security personnel.

His pugnacious campaign style, which includes personal insults directed at rivals and scathing criticism of protesters, has been criticized for encouraging physical altercations at his rallies.

Trump leads rivals Ted Cruz, a U.S. senator from Texas, and Ohio Governor John Kasich in opinion polls and in the number of delegates to the nominating convention, despite a concerted effort to stop him by a Republican establishment worried he will lead the party to defeat in November.

Cruz said Trump "of course" should ask for Lewandowski's resignation.

"Look, it shouldn't be complicated that members of the campaign staff shouldn’t be physically assaulting the press," Cruz said on the CNN town hall.

Kasich said he considered such behavior "totally and completely" inappropriate.

"If it was me, if I was in this circumstance, I would take some sort of action, either suspension or firing," Kasich told reporters in Wisconsin.