Haley Barbour has signed New Hampshire political operative Mike Dennehy to his political team, the latest sign that the Mississippi Republican governor is running for president in 2012.

“His charisma, personality and excitement for retail politics will make him an ideal candidate for New Hampshire should he decide to run,” Dennehy said of Barbour in a statement supplied to the Fix.

Dennehy gives Barbour immediate credibility among New Hampshire Republican insiders. Dennehy served as Sen. John McCain’s (R-Ariz.) New Hampshire campaign manager in 2000 and as national political director for McCain in 2008. McCain won the Granite State primary in each of those races.

Barbour has said he will not make a final decision on a presidential bid until the Mississippi legislature adjourns next month but his activity in the behind-the-scenes battle for staff talent suggests he is already in the race and running hard.

Earlier this month, Barbour announced that Jim Dyke, a former communications director at the Republican National Committee, would serve as an adviser to his political action committee. Dyke, who was one of the Fix’s top free-agent operatives heading into 2012, brings Barbour know-how at the national level as well as in the early primary state of South Carolina where he lives.

Barbour is clearly trying to build some momentum heading into his April announcement with these high profile hires but that effort has been stymied somewhat by a series of unforced errors. The latest came earlier this week when Barbour’s press secretary resigned following reports of an internal daily newsletter containing news clips and off-color humor that he sent around to allies of the governor. Barbour himself received a print out of the news clips that did not include the jokes.