CLEVELAND (AP) — It took just one question for chaos to erupt in Cleveland.

"Is there anyone on stage, and can I see hands, who is unwilling tonight to pledge your support to the eventual nominee of the Republican Party and pledge to not run an independent campaign against that person," asked Fox News' Bret Baier to kick off the first Republican debate of the 2016 campaign for president.

Only one hand went up, and with it, billionaire businessman Donald Trump sparked fresh waves of anxiety within the GOP as he went on to headline a debate that at times felt more like a circus than a forum for those who aspire to the White House.

The primetime ruckus on national television overshadowed some of the GOP's biggest stars, while creating fresh openings for others. But more than anything else, Thursday night's two-hour show — and Trump's presence made sure it was a show — was an in-your-face reminder the race for Republican nomination remains leaderless and unsettled.

The yelling erupted just minutes into the debate, when Trump answered Baier's question and refused to rule out a third-party bid should one of his many rivals beat him in the Republican contest.

"This is what's wrong!" Kentucky Sen. Rand Paul shouted from across the stage as the crowd booed Trump. "Maybe he runs as an independent. He's already hedging his bets."

The extraordinary opening moment set the tone for a night that was often entertaining, but often lacked the substantive and civil debate Republican officials had in mind when they tweaked their debate system to reduce acts of "Republican-on-Republican violence."

The reason why was all too clear.

"I think he's getting to a good place. This is new for him," said Republican National Committee Chairman Reince Priebus when peppered after the debate with questions about Trump's bombastic performance. "I think things are going to be just fine."

It didn't look that way during the rough-and-tumble start, when Fox News moderator Megyn Kelly asked Trump about his calling "women you don't like 'fat pigs, dogs, slobs, and disgusting animals.'"

Trump didn't deny it. And when Kelly was undeterred by his attempt to laugh off her question with a joke about comedian Rosie O'Donnell, he fired back.

"I don't frankly have time for total political correctness," Trump said. "And to be honest with you, this country doesn't have time either."

Trump's performance cooled down as the debate went on, but it still left little room for his Republican rivals to stand out on a night where each appeared to arrive with a clear strategy to do just that.

An authoritative Florida Sen. Marco Rubio distinguished himself by highlighting his foreign policy bona fides and moving personal story. Perhaps no one made more of his opportunities than home-state Gov. John Kasich, the two-term Ohio governor who snuck into the debate as the last candidate to win a place on stage.

Kasich drew repeated applause, particularly when showcasing his pragmatic approach to divisive social issues.

"I just went to a wedding of a friend of mine who happens to be gay," Kasich said when the conversation shifted to gay marriage. "Because somebody doesn't think the way I do, doesn't mean that I can't care about them or can't love them."

Not everyone was as successful at making the most of the limited amount of time they had to speak.

In his first opportunity to connect with a national audience, Wisconsin Gov. Scott Walker safely and calmly stuck to his script and his everyman image — and didn't produce a single "wow" moment.

Texas Sen. Ted Cruz, a champion college debater, was largely forgotten. His night was encapsulated by the moment he asked to "jump in on this one" — only to be told there wasn't time.

Tea party favorite Ben Carson was relegated to telling jokes, which, it should be said, drew heartfelt laughs from the crowd at Quicken Loans Arena.

New Jersey Gov. Chris Christie flashed his tell-it-like-it-is style in a blunt exchange with Paul, but also disappeared for long stretches of the night.

Former Florida Gov. Jeb Bush, the dominate front-runner in the all-important money race, tried to rise above the Trump-related squabbling. Having devoted several days to debate preparation, he came off as scripted in what was his first formal debate in more than a decade.

But Bush also avoided any major mistakes. He held fast to his policy priorities, such as an immigration overhaul, and engaged with Trump only briefly.

"Mr. Trump's language is divisive," Bush said.

"I want to win," he continued. "We're going to win when we unite people with a hopeful, optimistic message."

Thursday's affair was the first of only six Republican debates before voting begins next February, a sharp reduction in the number of face-to-face meetings from 2012. And with fewer debates, there are fewer opportunities for candidate to make their mark.

Yet no candidate will leave the race after this first clash. With money flowing freely to the outside groups known as super PACs, almost everyone in the race is backed by the money needed to spend on infrastructure and advertising that will shape — and reshape — voter's attitudes in the coming months.

That includes even the self-funded Trump, who may stick around longer than some people in the party may prefer. Republican strategist Liz Mair said the debate "has done Trump a tremendous disservice for exposing him for exactly what he is — a philosophically ungrounded, unappealing entertainer."

The former reality television star doesn't much seem to mind.

"I don't think they like me very much," he said of the debate audience. With a shrug.

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Associated Press writer Thomas Beaumont contributed to this report.

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Steve Peoples covers the GOP presidential campaign for The Associated Press. Follow him on Twitter at: http://twitter.com/sppeoples