Scratch Republican Haley Barbour off the list of presidential hopefuls for 2012.

The Mississippi governor made it official, he’s not running. It’s apparently all about that ”fire in the belly,” or lack thereof.

“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.  I cannot offer that with certainty, and total certainty is required,” Barbour said in a statement.

Readers of political tea leaves had some suspicions that Barbour might not run when Republican Tim Pawlenty snapped up Nick Ayers as  campaign manager for his exploratory committee. Ayers had been closely associated with Barbour as executive director of the Republican Governors Association when Barbour was chairman so it was a surprise when he went to work for another potential candidate.

Barbour’s wife, Marsha, earlier this month said a possible White House run by her husband ”horrifies me,” the task would be “overwhelming” and something she was not ready for. Barbour’s son, Sterling, in an email last month said he didn’t want his father to run.