Corey Lewandowski, the campaign manager for Donald Trump, appears to have been involved in another altercation in Tuscon on March 19. Trump has praised Lewandowski for his involvement in the incident. (Daron Taylor,Monica Akhtar/The Washington Post)

TUCSON — Donald Trump on Sunday doubled down on his team’s insistence that campaign manager Corey Lewandowski behaved appropriately while forcefully engaging with a protester at a rally here in Tucson on Saturday afternoon, commenting that local police and security appeared “a little lax” at the event.

Video footage shows Lewandowski and a man — who appears to be a plainclothes member of Trump’s security team — heatedly speaking to a protester. In a few seconds, the young man is suddenly pulled back by the collar. The protester then begins shoving the man to Lewandowski’s left.

The incident immediately sparked speculation on social media about whether Lewandowski was the one who yanked the protester and provoked the shoving, which the campaign denied in a statement on Saturday evening.

But even with no clear consensus on whether Lewandowski was responsible for the physical altercation, it is clear that he was involved in handling the protester. The incident puts him again at the center of a controversy involving appropriate security measures, sparking a debate about the propriety of a campaign manager being involved in handling protesters, particularly in the volatile environment that characterizes Trump rallies across the country.

Trump on Sunday praised Lewandowski’s efforts.

“I will give him credit, spirited,” the GOP presidential front-runner told ABC’s “This Week” on Sunday morning when asked about Lewandowski being in the crowd. “I give him credit for having spirit. He wanted them to take down those horrible profanity-laced signs.”

Lewandowski has been under heavy scrutiny since being accused of manhandling a Breitbart reporter earlier this month. The Trump campaign has strongly denied those allegations as well.

“Additional security measures will be put in place moving forward," Lewandowski said in a statement to The Washington Post on Saturday when asked about his participation in security efforts at future events.

[Trump campaign manager denies manhandling protester after video raises questions]

Trump indicated Sunday that Lewandowski’s participation in managing the protesters stemmed from uncertainty about the way police were handling the situation.

“Security at the arena, the police were a little bit lax. And… they had signs up in that area that were horrendous, that I cannot say what they said on the sign. But the ultimate word — and it was all over the camera — and, frankly, the television cameras can't take it and they can't do anything about it,” Trump said.

Trump himself has faced harsh criticism from detractors, who say he has set a tone that encourages violence at his campaign rallies. He strongly denies doing so. But violence has become a regular feature of Trump campaign events, culminating in a tense situation in Chicago involving brawls after one such event was canceled because of security concerns.

Trump has spoken dismissively about the violence at his events and has denied responsibility. He also has frequently winked at the incidents, saying at one event last month that he wanted to "punch a protester in the face" and telling supporters at other times that he would pay their legal bills if they got involved in physical altercations with demonstrators.

At the Tucson rally on Saturday, a man sucker-punched and stomped on a protester being escorted out by police. The protester's friend, who was also being escorted out, was wearing a Ku Klux Klan hood. Trump said Sunday that the costume enraged the assailant, who was black.

“Frankly, that was a, you know, it was a tough thing to watch. And I watched it,” Trump said. “But why would a protester walk into a room with a Ku Klux Klan outfit on?”

The incident carried echoes of an assault in Fayetteville, N.C., earlier this month in which a man slipped past security and sucker-punched a protester as he was being led out of the venue.

"These are professional agitators, and I think that somebody should say that when a road is blocked going into the event so that people have to wait sometimes hours to get in, I think that's very fair and there should be blame there, too," Trump added later in the interview.

"When signs are put up, lifted up with tremendous profanity on them, I mean the worst profanity," he continued, "and you have television cameras all over the place and people see these signs, I think maybe those people have some blame and should suffer some blame, also."