CLEVELAND — 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.