New York (AFP) - Republican frontrunner for president and brash billionaire Donald Trump pledged loyalty to the Republican Party and ruled out a third-party tilt for the 2016 election.He made the announcement in the lobby of his New York headquarters as he shot to an even greater lead with 30 percent of the Republican-leaning vote, according to the latest opinion poll by Monmouth University."I will be totally pledging my allegiance to the Republican Party and the conservative principles for which it stands," the real estate tycoon told a news conference at Trump Tower."We will go out and we will fight hard and we will win.