Cullen headed the state party in 2007 and 2008, during which time the GOP picked up 17 seats in the Legislature. He also writes a regular column for the Manchester Union Leader — which has endorsed Newt Gingrich.
Cullen was on the fence heading into the weekend about whether Huntsman or Mitt Romney deserved his support. But he said he came to a decision just ahead of Tuesday's first-in-the-nation primary in the Granite State after watching Huntsman's performances in a pair of weekend debates, as well as his handling of a flare-up over a video that Ron Paul supporters released mocking Huntsman's foreign-born adopted daughters.
"I care about someone who can actually win a general election by appealing to centrist voters, not just partisan activists," Cullen said. "And he's worked so hard in New Hampshire, I think he deserves credit for that. He's earned it."