WASHINGTON -- The first debate of the U.S. presidential election cycle was only a moment old and arguably wilder than anything that's ever happened in a Canadian TV debate including Thursday's.

That's because Canadian politics doesn't have anybody like Donald Trump.

As the Canadian debate entered halftime, Republican presidential candidates hit the stage with the swirly haired political hurricane smack in the middle, settling at the prized centre-podium reserved for the primary poll-leader.

Within mere minutes Trump had threatened to run against his own party; insulted actress Rosie O'Donnell; and accused the moderator of being biased against him.

Boos rained down on the boastful billionaire as he refused to promise he wouldn't run against Republicans should they nominate someone else.

The moderator had asked the 10 participants to raise their hand if they wouldn't swear off a run against Republicans. Only one hand shot up -- Trump's.

The incredulous moderator cut in: This is a Republican party event, he asked Trump, and you're saying you'd be willing to run against this party, split the right-wing vote, and guarantee a Democratic win?

Perhaps, Trump replied.

"I cannot say," Trump elaborated, to groans from the crowd.

"I have to respect the person if it's not me ... I will not make the pledge at this time."

That prompted Sen. Rand Paul to interject: "He buys and sells politicians of all stripes. He's already hedging his bets on the Clintons... because he's used to buying politicians."

Another moderator then asked why Trump's candour -- while sometimes refreshing -- includes a mean streak in which he's publicly referred to women as fat pigs, dogs, slobs and disgusting animals.

Trump stopped her: "Only Rosie O'Donnell." He went on to express pride in eschewing political correctness, which drew some cheers from the Cleveland crowd. Trump also scolded the co-moderator, Megyn Kelly, for being unfair to him. She'd noted his insults extended far beyond O'Donnell.

Such jaw-dropping moments might explain why the fascination with Trump stretches across international boundaries. He's not only creating waves in the U.S., he's also crushing Canada's party leaders when it comes to Google searches.

According to Canadian Google searches in the past 30 days, Trump got nearly the same number of searches as Stephen Harper, Justin Trudeau and Thomas Mulcair combined.

Figures provided by Google shown that among searches for the Canadian leaders and for the Democratic front-runner Hillary Clinton, Trump got 42 per cent; Harper got 27; Trudeau got 17; Clinton got nine; and, despite his NDP leading recent polls, Mulcair had only five per cent.

Trump squeezed in a Canada reference Thursday.

He was asked about his past support for single-payer medicine and replied: "It works in Canada. It works incredibly well in Scotland. It could've worked (here) in a different age." He called the U.S. health system corrupted by insurance companies, and said he now favours breaking barriers between state exchanges to allow nationwide competition.

When Paul attacked him again, accusing him of still favouring socialized medicine, Trump replied: "I don't think you heard me -- you're having a hard time tonight."

The American political world had speculated that the fascination with the outlandish mogul could lead to record ratings for Thursday's Fox News debate, which started an hour after the Canadian leaders debate.

Trump even became an issue in a debate he wasn't part of Thursday. The topic of his candidacy came up in the so-called kiddie-table debate, consisting of candidates who didn't make the Top 10 for the prime-time show.

Former Hewlett-Packard CEO Caryl Fiorina, whom Fox pundits later unanimously deemed as the most impressive participant, said Trump had managed to connect with a grumpy American public.

"I think he's tapped into an anger that people feel. They're sick of politics as usual," she said.

But she also took a little shot at him -- for flip-flopping on some issues where he once held liberal positions, like his one-time support for abortion and single-payer, Canadian-style health care.

She noted that he'd also donated to both Clintons' campaigns.

Republicans have started to challenge Trump's conservative credentials. Because those who tried a previous line of attack -- calling him an ill-informed buffoon -- saw it backfire.