Billionaire businessman Donald Trump has stunned American politics by refusing to guarantee he wouldn’t run as an independent against the winning Republican candidate.

The top 10 Republican nominees at the fiery debate in Cleveland were asked if any would run for the White House with no political party, should their nomination fail.

Only Mr Trump raised his hand.

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“I cannot say I have to respect the person [the winning candidate] if it’s not me,” Mr Trump said. “I can totally make the pledge if I am the nominee I will not run as an independent.”

“I’m talking about a lot of leverage, we want to win and we will win.”

Before we start, I’d like any of the candidates who want Hillary Clinton at their wedding to raise their hand. #Trump pic.twitter.com/liiCXAPeqj

— Josh Jordan (@NumbersMuncher) August 7, 2015

Mr Trump qualified for the debate as the top ranked Republican candidate going on the aggregate score of the last five nationwide polls.

Should he stay in that position, it will most likely be Mr Trump against Hilary Clinton in the November 2016 US Election.

That revelation was the first of many moments of bravado, crowd adulation and disagreement at the debate, where some strengthened their chances of entering the White House, and others wilted.

On the agenda were a whole range of hot-button topics including abortion, same-sex marriage, gun control and foreign policy.

Jeb Bush wanted voters to know he is not living in the shadow of his Dad or brother. Photo: ABC

Trump on women

Mr Trump has had a long history of disparaging remarks toward women and one of the debate moderators wasn’t going to let that go.

Megyn Kelly started to ask Mr Trump: “You’ve called women you don’t like, ‘fat pigs,’ ‘dogs,’ ‘slobs,’ and ‘disgusting animals’…”.

Mr Trump interrupted her to clarify: “Only Rosie O’Donnell.”

He didn’t apologise for the joke, or any of his previous comments.

“It’s fun, it’s kidding, we have a good time,” he said. “If you don’t like that I’m sorry … I think the big problem this country has is being politically correct.

“I frankly don’t have time for total political correctness. We lose to China, we lose to Mexico in trade and at the border. What I say is what I say.”

Rand Paul on guns and gays

The right to bear arms and same-sex marriage – they’re two of America’s most contentious issues and they’re both allowed, thanks to strong lobbies in their favour.

Rand Paul made his stance on touchy topics crystal clear. Photo: AAP

Responding to a question about the recent US High Court decision to allow same-sex marriage, the Kentucky Senator was blatantly clear how he saw the polarising subjects.

“I don’t want my marriage or my guns registered in Washington.”

Blame pimps for welfare rorts

Governor Mike Huckabee was talking about the United States’ social welfare system and said:

“Illegals, prostitutes, pimps, drug dealers, all the people who are freeloading off the system now”, need to be stopped.

He was abruptly cut short by the host, quick to nip anymore controversial comments in the bud.

God and government’s girth

One of the home viewers wanted to know if God had told any of the candidates what they should take care of first, if they won office.

Detroit neurosurgeon Ben Carson went straight for heaven – on an unrelated question –  when he said God is “a pretty fair guy”.

It’s unclear what this had to do with cutting the size of government, the topic at the time but he added: “I have more to say on this.”

Unfortunately he didn’t get that chance.

The Top 10 Republican candidates line up before the controversial debate in Cleveland. Photo: AAP

Trump: America has “stupid” leaders

Mr Trump is of the view that the Mexican government purposely send its criminals over the border into America.

Because he feels the American government doesn’t do enough to stop this, he thought he’d offer his solution.

“We need to build a wall and it has to be built quickly,” Mr Trump said. “I don’t mind having a door in that wall so people can come in legally.”

“The Mexican government send the bad ones over because they don’t want to pay for them.

“Why should they when the stupid leaders of the US will do it for them?”

Exactly what does the military do?

Mike Huckabee offended pimps, illegals, transgenders and drug dealers. Photo: AAP

Mr Huckabee answered the question for anyone wondering.

“The military is not a social experiment. The purpose of the military is to kill people and break things.

“Im not sure how paying for transgender surgery … makes America safer.”

Serious brotherly banter

George W. Bush’s brother and 2016 Republican hopeful Jeb Bush has repeatedly dodged questions about his sibling’s decision to go war in Iraq.

He finally answered the question in Cleveland: “Knowing what we know now … it was a mistake. I wouldn’t have gone in,” he said.

“ISIS was created because of the void that we left.”