Trump refuses to rule out independent White House run

Republican frontrunner Donald Trump threw the party's first major election debate into chaos Thursday, refusing to pledge allegiance to the party and walk back sexist comments.

The prime-time debate opened with a call for the 10 candidates on stage in Cleveland, Ohio to raise their hand if they pledged to refuse to back the eventual party nominee and rule out an independent run.

A sole hand rose in the air -- that of Trump, the brash, unorthodox billionaire who is the improbable party frontrunner, as jeers rippled around the rambunctious crowd.

"I will not make the pledge at this time," he said, drawing an angry exchange with Senator Rand Paul.

"He's already hedging his bets because he's used to buying politicians," Paul shouted across the stage.

"I've given you plenty of money," Trump shot back.

He was later asked to roll back disparaging comments about women, to which he responded: "I think the big problem this country has is being politically correct."

"I don't frankly have time for total political correctness."

In the early days of the 2016 election cycle, Trump has bested career politicians, some of whom have spending half a lifetime preparing for a run at the White House.

But it's still early days, and the Republican electorate is fractured -- poll leader Trump has the backing of just 24.3 percent of respondents.