Update: Donald Trump plans to endorse Mitt Romney, a Romney campaign official said this morning.

Real-estate tycoon Donald Trump jetted into Las Vegas Wednesday night with plans to throw his unorthodox backing–and maybe even some of his fortune–behind Newt Gingrich‘s presidential campaign.

The announcement, confirmed by people within the Gingrich campaign, is yet more evidence of the widening gap within the GOP between the more insurgent conservatives who are jumping on the Gingrich bandwagon and the establishment roster of mainly elected officials who are now backingMitt Romney.

Mr. Romney has won the support of establishment favorites such as New Jersey Gov. Chris Christie and former Minnesota Gov. Tim Pawlenty, while Mr. Gingrich is attracting the backing of a more rambunctious, tea-party-infused following, including Herman Cain, former Alaska Gov.Sarah Palin, Texas Gov. Rick Perry and now Mr. Trump.