Trump vows no third-party bid, will back GOP primary winner

NEW YORK -- Caving to intense Republican lobbying, presidential candidate Donald Trump ruled out the prospect of a third-party White House bid Thursday and vowed to support whoever wins the party's nomination -- a U-turn made easier by his position at the front of the field.

The decision follows weeks of behind-the-scenes efforts by GOP leaders, who've been trying to avert the possibility of an independent campaign by Trump ever since last month's opening debate, when he refused to promise to back the party's eventual nominee.

A third-party bid by any prominent conservative could doom Republican efforts in 2016.

"I will be totally pledging my allegiance to the Republican Party and the conservative principles for which it stands," Trump said in a news conference at Trump Tower, the gold-hued skyscraper in midtown Manhattan where he launched his surging campaign for president.

The 69-year-old billionaire, who announced his decision after meeting Republican National Committee Chairman Reince Priebus, insisted he got "absolutely nothing" for pledging his loyalty "other than the assurance that I'll be treated fairly."

Priebus did not comment, but it was clearly a positive result for GOP leaders in what has been an unpredictable presidential primary season.

To their dismay, Trump has emerged as the overwhelming front-runner in a crowded field, despite repeatedly insulting key constituencies and offering few details about his policies.

The reality television star has described Mexican immigrants as rapists, questioned Sen. John McCain's war-hero status and insulted a popular Fox News host.

And his refusal to pledge his support for the GOP primary campaign winner, if he falls short, further roiled the party.

The document Trump signed Thursday is a pledge, not a contract. Even if it were legally binding, Trump's history in contract law is suspect.

When lender Boston Safe Deposit & Trust refused to extend the mortgage on his Palm Beach resort, Mar-a-Lago, he ceased making loan payments until the bank capitulated in 1992.