Some of Donald Trump’s Republican rivals predicted Sunday that he will not win the party’s nomination for president, as the billionaire businessman bragged that terrorist attacks actually strengthen his campaign because people see him as a strong leader.

In an interview Sunday on CBS’s “Face the Nation,” Trump defended profiling Muslims, arguing that the San Bernardino couple who fatally shot 14 people and wounded 21 might have been stopped if people who knew them, including relatives, had not been worried about being "politically correct."

“A lot of people knew what was going on in that house or that apartment. And people were not wanting to call because they thought it would be inappropriate to call ... that they would've been profiling," Trump said. "And a person said, 'We sort of knew what was going on, but we don't want to profile.' Can you believe this?”

John Dickerson, host of the show, asked Trump whether he was suggesting profiling, Trump said: “Well, I think there can be profiling. If they thought there was something wrong with that group and they saw what was happening, and they didn't want to call the police because they didn't want to be profiling, I think that's pretty bad. People are dead. A lot of people are dead right now.  So everybody wants to be politically correct, and that's part of the problem that we have with our country.”

Trump also repeated his argument for tracking Muslims, as issue over which he has faced harsh criticism. "You have people that have to be tracked. If they're Muslims, they're Muslims. But you have people that have to be tracked," Trump said. "And we've better be — I use the word vigilance. We have to show vigilance. We have to have it. And if we don't, we're foolish people."

The candidate also said that he didn’t believe the sister of one of the shooters, Syed Rizwan Farook, who has said in interviews that she had no idea that her brother was planning the attack.

“I probably don't believe the sister,” Trump said. “I would go after a lot of people and I'd find out whether or not they knew. I'd be able to find out. Because I don't believe the sister.”

Ohio Gov. John Kasich, in an interview on CNN’s “State of the Union,” dismissed the notion of going after the families of suspected terrorists. “I don’t think so,” he said in response to a question by host Jake Tapper.

Kasich defended an ad that some have said unfairly compares Trump to Nazis and said, “I believe that Donald Trump will not be the nominee.”

“I think things will settle down. And I believe, at the end of the day — and what I have heard in New Hampshire is — is experience is what counts, somebody who has been a reformer, but somebody who has experience,” Kasich said.

Jeb Bush, who appeared on ABC’s “This Week,” seconded that notion.

“Donald Trump is not going to get the nomination. I have enough confidence in the Republican primary voters in these early states and beyond. I'll trust them to make that decision,” Bush said. “I know for a fact that a conservative is not going to win unless they have a hopeful, optimistic message, and, after all, our ideology is much more hopeful and optimistic than the progressive left. And so I'm sticking to my guns on that. It's who I am. I need — you need to be authentic when you run.”

Clinton, who appeared earlier on “This Week,” laughed out loud when host George Stephanopoulos mentioned Trump’s name.

“I'm sorry. I can't help it,” she said.

Asked why she thinks Trump is doing so well, Clinton said, “Because he's a reality TV star. I mean tens of millions of people have watched him for more than a decade on TV, and he is part of the celebrity, and he will say whatever he wants to say, and if he's held to account, that — it's not true, he just brushes it off and he goes on. And I think that, you know, there's a certain attractiveness to people that here's a guy who says exactly what he believes, untrue as it may be, inflammatory as it certainly is.

Trump had been scheduled to do a telephone interview on CNN, which released a poll on Friday showing him leading the Republican field with 36 percent of the vote. But the interview was scratched because of technical difficulties.

During a rally Saturday in Iowa, Trump boasted that his support has grown since the Nov. 13 Paris terrorist attacks, according to Politico. “Every time things gets worse, I do better. Because people have confidence in me,” he reportedly told a crowd of about 2,500 in Davenport. “People want strength,” he said.

During Sunday’s interview, Trump seemed to break with other GOP candidates on the question of whether people on terrorist watch-lists and no-fly lists should be able to buy guns.

“Well, I'd certainly take a look at it. I would. I'm very strong into the whole thing with Second Amendment — but if you can't fly, and if you've got some really bad — I would certainly look at that very hard,” Trump said.

But at another point in the interview, he suggested that if the victims in San Bernardino, as well as Paris, had had guns, they could have better resisted their attackers.

“We have to be looking at a lot of different things, but we can't do anything to hurt the Second Amendment. People need their weapons to protect themselves, and you see that now more than ever before,” Trump said.

New Jersey Gov. Chris Christie, appearing on CBS’s “Face the Nation,” dismissed Trump’s suggestion that profiling Muslims would be helpful.

“The fact is, we don't need to be profiling in order to be able to get the job done here. Increased surveillance, creating relationships with mosques in the Muslim American community across the country, we did that after 9/11 and prevented attacks in New Jersey and all across the country,” Christie said. “What you need is a president who has had the experience and the know-how to do this, and not someone who is just going to talk off the top of their head.”