Jon Huntsman campaign manager resigns

Republican presidential candidate Jon Huntsman's campaign manager has stepped down.

The Huntsman campaign cast campaign manager Susie Wiles' departure as part of the campaign's shift to "phase two," which adviser John Weaver described as "more aggressive from a messaging and tactical standpoint." The campaign said Wiles is being replaced by communications director Matt David.

The Huntsman team was quick to suggest Wiles' departure simply reflected a planned move forward - not a sign of trouble - with Weaver saying Wiles "served the campaign well and was vital in getting it off the ground in such a short time-frame." The campaign pointed CBS News to Wiles' comments to the Miami Herald, where she said she had always planned to "resign at some point."

"The only thing that's surprising is the exact day, not the fact I'm leaving," she told the newspaper. "This is a natural progression of a campaign." Wiles said her time running the campaign was "like a phase," saying she "signed up to get it started." Wiles is the only member of the campaign whose departure was announced.

But if Wiles' departure isn't a sign of the sort of campaign implosion that Newt Gingrich faced earlier this year, it still suggests turmoil. Despite plenty of buzz in the beltway, Huntsman, a moderate former Utah governor, is barely registering in polls of the Republican candidates; the conventional wisdom in Washington is that he would be a potentially strong general election opponent against President Obama but will struggle to win over the conservative Republican primary voters who could decide the party's nominee. Weaver's comment that the campaign will now shift to a "more aggressive" tone suggests that Huntsman is poised to start drawing stronger contrasts with his rivals.

Wiles, who ran Rick Scott's successful Florida gubernatorial campaign, had been a surprising choice to run Huntsman's campaign, and prompted concerns that the campaign lacked a broad national management structure.

The Washington Post's Aaron Blake, who broke the news, notes that new campaign manager David was a top communications aide for former California Gov. Arnold Schwarzenegger. Like Weaver, he is a veteran of Republican presidential nominee John McCain's 2008 campaign.