Donald Trump the wild card in 1st Republican debate

Donald Trump has been referred to as a rattlesnake and a drunk NASCAR driver by other campaigns, but the candidate himself says he's a nice person who isn't looking to get nasty in tonight's first Republican debate.

The 10candidates leading in the polls will take the stage in Cleveland for two hours in a prime-time event sponsored by Fox News, in co-ordination with Facebook.

In a crowded field of Republican candidatesthere are 17 in totalTrump hasgrabbedthe most attention in the lead-up to the debate. He is the one candidate the others are developing a strategy around and who perhaps has the most riding on his performance, because all eyes are on him.

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People are asking what version of Trump will show up in Cleveland:The blunt, confident, some might say arrogant, Trump, who has already made his share of eyebrow-raising if not outrageous and offensive comments? Orwill he soften his tone and try to appear more serious andpresidential, with some concrete policy proposals beyond keeping Mexican "rapists"out of the U.S.?

Trump himself saidhe's entering the debate uncertain of how he'll perform.

"I'm not a debater I've never been on a stage debating," he told Chuck Todd on NBC'sSunday political show.

While he admits he is inexperienced, Trump isn't hunkering down with strategists and coaches the way other candidates tend to prepare for debates. Some of the candidates were practising in mock debates in recent days, whileTrump flew to Scotland to one of his golf courses, whichwas hosting the Women's British Open tournament.

"I think I know most of the subjects very well," he told Todd. "We'll see what happens. But again, I don't think you can artificially prepare for something like this."

Insults already traded

One of Trump'sadvisers told the Washington Post that the candidate's preparations are "low key" and that Trump will get his views across in "a way that is not programmed."

Tough words, and insults, have already been traded between the campaigns, so viewers could see some fireworks when the candidates come face to face.

One of Marco Rubio's advisers said Trump is like "a rattlesnake with a toothache."

"He's the worst kind of guy to have up there, because you have no idea who he's going to go after," the unnamed adviser said in a Politico report.

"Imagine a NASCAR driver mentally preparing for a race knowing one of the drivers will be drunk," wrote John Weaver, senior adviser to candidateJohn Kasich,on Twitter. "That's what prepping for this debate is like."

Candidate Rick Perry, former Texas governor, called Trump's run for president a "cancer on conservatism" that must be excised and discarded. He hassaid that Trump offers a mix of "demagoguery and nonsense."

Trump, for his part, has said that Perry should be forced to take an IQ test before being allowed to participate in the debate and that he started wearing glasses to try to look smart. "It just doesn't work. People can see through the glasses," Trump said at a campaign event.

Another candidate, SenatorLindsey Graham, has called Trump uninformed and a wrecking ball for the Republican Party and a jackass. Trump, in turn, gave out Graham's personal cellphone number before a throng of television cameras.

Trump's competition has to decide how they want to handle him. He's the front-runner in the polls, a fact some find shocking, but do they engage him or ignore him?

Trump like 'nitroglycerine'

Trading barbs with Trump could guarantee a soundbite in the post-debate media coverage and generate buzz for days after, which is attention that candidates need to stand out in a crowded field.

But directly interacting with Trump could be risky, particularly if the real estate mogul and reality TV star responds aggressively. Republican commentator Newt Gingrich said Trump is prepared to say virtually anything and "it's like dealing with nitroglycerin."

The other candidates may not want to make him the focus of attention either. He's already been getting a lot of it, and they will each have limited time to talk. If they use that time to dump on Trump, they may not get a chance to tell voters where they stand on key issues.

Wisconsin Gov.Scott Walker told reporters last week that he's not factoring Trump into his debate plan. "I'm just going to tell people what I'm for. So it doesn't matter to me whether he's on the attack or not," he said.

Thursday's debate will be the first chance for candidates to appeal to voters on a national, prime-time stage, and some are bound to shine brighter than others.

After this debate, there will be eight more to go.