Prime-Time GOP Debate: Trump Clashes With Bush But Pledges Party Loyalty

While the nine leading Republican presidential candidates argued tonight over who'd be best to keep the U.S. safe, and asserted they'd all do better than President Obama, perhaps the biggest news was Donald Trump saying he wouldn't run as an independent or third-party candidate, should he fail to win the Republican nomination.

In the mainstage debate at the Venetian in Las Vegas, televised on CNN, moderator Wolf Blitzer asked Trump toward the end if he was ready to commit not to running outside the party and to support whoever is the nominee. "I really am," the business tycoon responded. "I gained great respect for the Republican leadership. ... I will tell you: I am totally committed to the Republican Party. I feel very honored to be the front-runner."

Ben Carson, the retired neurosurgeon who has identified like Trump as an "outsider" candidate, also said he wouldn't leave the party, as he had threatened to do if GOP leaders tried to deny Trump the nomination even if he went into next summer's convention with a leading delegate count. Carson said he's been assured that won't happen, and that a Washington Post report that Republican insiders are working on such a plan was inaccurate.

The debate, which focused on foreign policy and national security, especially how best to fight the terrorist group ISIS, featured several contentious exchanges. Some were between Trump and former Florida Gov. Jeb Bush, with Bush saying he's better qualified than Trump to deal with Russian President Vladimir Putin and other world leaders because "I know what I don't know." He said he'd seek the best advice possible from foreign policy experts.

Trump, Bush said, gets his information from "the shows," and Bush questioned whether that's the Sunday morning shows (news) or Saturday morning )children's fare). He said Trump is not a serious candidate. He's "great at the one-liners, but he's a chaos candidate," Bush said. "And he'd be a chaos president." He also decried Trump's call to prevent Muslims from immigrating to the U.S.

Trump responded, "Jeb doesn't really believe I'm unhinged [as Bush recently said]. He said that very simply because he has failed in this campaign. It's been a total disaster."

Later, Bush said, "Look, two months ago Donald Trump said that ISIS was not our fight. Just two months ago he said that Hillary Clinton would be a great negotiator with Iran." At another point, Bush told Trump, "You're never going to be president of the United States by insulting your way to the presidency." Trump came back with "I'm at 42, and you're at three," referring to their respective percentages of support in Republican polls. "So, so far, I'm doing better."

Other candidates, including former Hewlett-Packard CEO Carly Fiorina and Ohio Gov. John Kasich, called on Bush and Trump to stop the fighting. "This doesn't do a thing to solve the problems," Fiorina said, while Kasich noted, "It is not the way we're going to strengthen our country. We will strengthen our country when we come together."

New Jersey Gov. Chris Christie and U.S. Sen. Rand Paul of Kentucky had a fight of their own over Christie's statement that he'd impose a Russian no-fly zone over Syria and shoot down any planes that violated it "if in fact they were stupid enough to think that this president was the same feckless weakling that the president we have in the Oval Office is right now."

Paul responded, "It's a recipe for World War III. ... I think when we think about the judgment of someone who might want World War III, we might think about someone who might shut down a bridge because they don't like their friends," referring to the 2013 lane closures on the George Washington Bridge, allegedly because of a feud between Christie and the mayor of Fort Lee, N.J. Christie's former chief of staff is on trial for her role in the closures, and although an internal probe found no wrongdoing on Christie's part, he has been tainted by the matter.

Other issues that came up in the debate included whether attempting to topple dictators overseas is a good idea. "Regime change hasn't won," said Paul. "Toppling secular dictators in the Middle East has only led to chaos and the rise of radical Islam." He also denounced some national security measures, such as the bulk collection of Americans' phone data, as ineffective and a violation of privacy rights.

U.S. Sen. Ted Cruz of Texas also expressed opposition to regime change, such as the possibility of undermining President Assad in Syria, saying, "We ought to hunt down our enemies and kill ISIS rather than creating opportunities for ISIS to take control of new countries."

Marco Rubio, the U.S. senator from Florida, said he "wouldn't shed a tear" is Assad were deposed, but Cruz replied, "It's more than not shedding a tear. It's actively getting involved to topple a government. And we keep hearing from President Obama and Hillary Clinton and Washington Republicans that they're searching for these mythical moderate rebels. It's like a purple unicorn. They never exist. These moderate rebels end up being jihadists.

But Kasich asserted, "I don't understand this thing about Assad. He has to go. Assad is aligned with Iran and Russia. The one thing we want to prevent is we want to prevent Iran being able to extend a Shia crescent all across the Middle East. Assad has got to go."

On regime change, Trump got in a dig at the invasion of Iraq under Jeb Bush's brother, President George W. Bush. "In my opinion, we've spent $4 trillion trying to topple various people that frankly, if they were there and if we could've spent that $4 trillion in the United States to fix our roads, our bridges, and all of the other problems; our airports and all of the other problems we've had, we would've been a lot better off," he said.

Rubio and Cruz also clashed over immigration, with Rubio favoring a path to legal status for undocumented immigrants to the U.S. and Cruz saying he will never support legalization. Among all the Republican candidates there was skepticism about allowing refugees from war-torn Syria into the U.S., with the candidates saying it would be too difficult to screen them for radical sympathies.

And social issues, LGBT issues included, were largely absent from the debate. The only dog whistle was in Rubio's opening statement, when he alleged that today in the U.S., people are "called bigots because they hold on to traditional values."

For even more on the debate, you can check out The Washington Post's annotated transcript here.