DECEMBER 15 — Donald J. Trump kept his focus on multiple polls showing him leading the Republican presidential primary race while talking at length yesterday about immigration and the country’s economy during a speech here before thousands of people.

Trump addressed the crowd gathered at the Westgate Las Vegas Resort and Casino for an hour, at times mocking both his Republican and Democratic opponents and promising to improve America’s financial standing in the world. He also reminded the audience that he is funding his own campaign, casting himself, as usual, as an outsider candidate.

“This country needs to get away from political correctness. It’s killing us,” he said to loud applause. “I’ll never be a politician. I don’t want to be a politician.”

He criticised other candidates for using speechwriters and said he spoke without using notes and relied on a good memory.

Protesters interrupted the event several times and were led out, with the crowd cheering their exit each time. At one point, in a video captured by a BuzzFeed reporter, a Trump supporter yelled for one demonstrator to be set on fire as security guards restrained him.

As the event continued to be interrupted by protesters’ outbursts, other supporters shouted, “Trump,” “We want Trump,” and “You can’t stop Trump.”

During the scuffles, Trump took aim at the news media and chastised reporters for turning their cameras toward the disruptions. Later, he told supporters that they should have been staging protests of their own.

“We have a silent majority that is actually a noisy majority,” Trump said. “But, we should have been doing what they’re doing for the last seven years because what’s happening to our country is a disgrace.”

Trump again took aim at the decision to allow refugees from Syria into the United States and vowed to deport them if elected. “They are going back if I win,” Trump said. “They are going back. They have to.”

He added that France’s tough gun laws may have impeded people from defending themselves during last month’s deadly attacks in Paris.

“Paris has the toughest gun control just about in the entire world,” Trump said. “If a few of those people — that are now dead — if a few of those people had guns strapped to their ankles or strapped to their legs, you wouldn’t have the problem.”

At one point, Trump brought onstage a man who said an undocumented immigrant had shot his son. “We don’t know what’s going on and that’s why we need Donald Trump,” the man said. “He feels what we feel. He’s just like us.”

Trump’s message resonated with many supporters, who cheered at length each of his ideas.

Davor Jedlicka, 70, a retired professor living in Las Vegas, said he plans to vote for Trump because he appreciates the candidate’s honesty and his immigration policies.

“People are too hung up on rhetoric,” Jedlicka said. “You don’t start a debate with a reasonable position. If you had a reasonable position, you wouldn’t win the debate. So you start with a bomb. You start out making an extreme statement, then you work toward the middle until there’s reason.”

Kris Smith, 63, a retired state police sergeant, also plans to vote for Trump. He pointed to Trump’s plan to build a wall between Mexico and the United States and said he supported his proposal to bar Muslims from entering the United States.

“We can’t vet who the Muslims are,” said Smith, who flew to Las Vegas for the event from his home in Pocatello, Idaho. “We don’t know whether they are terrorists. We already know that ISIS has Syrian passport machines. So we don’t know who is coming in.”

Trump said that if elected he would review the case of Sgt. Bowe Bergdahl and would open an inquiry into Hillary Clinton, without offering details. And despite some polls showing candidates like Sen. Ted Cruz of Texas improving their numbers among potential voters, Trump said he expected to win Iowa and Nevada.

“The American dream is dead, but we are going to make it bigger and better and stronger,” Trump said, concluding his speech. “And we are going to make America great again.” — The New York Times