Mississippi Governor Haley Barbour isn't running for president, after all.

In a statement this afternoon, Barbour said he couldn't offer the kind of committment it takes to successfully mount a campaign for the White House.

"A candidate for president today is embracing a ten-year commitment to an all-consuming effort, to the virtual exclusion of all else. His (or her) supporters expect and deserve no less than absolute fire in the belly from their candidate," in the statement, quoted by Politico. "I cannot offer that with certainty, and total certainty is required."

Barbour has a vast network of Republican connections from his days as head of the Republican National Committee and the Republican Governors Association, and it was thought he might be able to raise the money necessary for a competitive bid.

But Barbour also worked for many years as a lobbyist, and some wondered if the complicated racial history of his home state--combined with Barbour's thick Southern accent--might make it difficult for him to connect with voters outside the South. Questions about the White Citizens Council and Nathan Bedford Forrest had already begun to dog Barbour.

A field that looked crowded a few months ago is beginning to seem awfully thin, as Barbour joins George Pataki in ruling out a race, and observers have begun to doubt the seriousness of some who were thought to be contenders, like Mitch Daniels and Sarah Palin.

That leaves '08 re-treads Mitt Romney and Mike Huckabee, and a slew of new candidates--Tim Pawlenty, Michele Bachmann, Herman Cain--who have yet to garner much attention. Whether there's enough of an opening for one of the New Yorkers still considering the race--Rudy Giuliani, quietly; and Donald Trump, more loudly--remains to be seen.