Donald Trump drew boos from the crowd and an attack from a rival at a raucous first Republican US presidential debate after he refused to rule out an independent bid for the White House and bristled at questions about his attitudes towards women.

With 10 Republicans vying for attention on the crowded stage on Thursday night in Cleveland, Ohio, the candidates frequently turned on one another rather than direct their fire towards Democratic frontrunner Hillary Clinton or President Barack Obama.

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Standing at centre stage by virtue of his lead in opinion polls, the property billionaire kicked off the debate by raising his hand when the moderators asked if any of the candidates would not pledge to support the Republican nominee in the November 2016 election.

"I will not make the pledge at this time," said Trump, who has said for weeks that he would not rule out an independent bid, especially if he felt he was mistreated by the party.

An independent run for the White House by Trump would be likely to split the Republican vote, boosting the chances of victory for Clinton or another Democrat.

Trump's response drew boos from the crowd and a rebuke from Senator Rand Paul, who said Trump was keeping his options open to support Clinton, a veiled reference at his past friendship with both Clinton and her husband, Bill.

Al Jazeera's Tom Ackerman, reporting from Cleveland, said that while the debate was not all about Trump, it was hard for moderators and other contenders to "avoid dealing with him".


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Pressed by Fox News moderator Megyn Kelly about past derogatory comments he had made about women, including calling them "fat pigs," "dogs" and "slobs," Trump dismissed the question as "political correctness" and accused Kelly of not treating him well, drawing more boos from the audience.

"Rather than being apologetic or pulling back - he gave no quarter," said Ackerman, adding that for the rest of the debate, the contenders largely agreed with each other on the major issues.

As in the 2012 Republican primaries, the party faces a tug of war between those eager for a candidate with broad general election appeal and those who think the key to winning is nominating a fiery conservative.

Four years ago, the establishment favoured Mitt Romney, but he struggled to gain the support of conservatives who dominate the state-by-state primary contests that choose the party candidate.


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Standing to Trump's left on the debate stage on Thursday night was former Florida Governor Jeb Bush, a favourite of the wealthy donors and business leaders that populate the establishment wing of the Republican Party.

But Bush, the son and brother of two former US presidents, has struggled to separate himself from the rest of the field and faces questions about whether his nomination would mark a return to the past.

Immigration and counterterrorism dominated the early stages of the debate, two issues that highlight the deep divisions within the Republican Party.

Bush, whose wife was born in Mexico, defended his call for a path to legal status for some of the people living in the US illegally.

The former governor's stance is an unpopular position among some Republican voters who equate legal status with amnesty.

Source: Al Jazeera and agencies