(CNN) - Mitt Romney is in South Carolina Thursday signing copies of his new book and campaigning for state Rep. Nikki Haley, who is seeking the Republican nomination for governor. Haley backed the former Massachusetts governor during his 2008 bid for the Republican presidential nomination.
But Romney's endorsement of Haley in the South Carolina governor's race, which he announced last month, puts him at odds with a number of party leaders in the crucial primary state who supported him during the 2008 presidential race. Many of them, including the operatives who ran his presidential campaign in the state, are backing one of Haley's rivals in the crowded GOP primary, Rep. Gresham Barrett.
Two of Romney's three campaign chairmen - former Gov. Jim Edwards and former Rep. Tommy Hartnett - are supporting Barrett. So are two co-chairs of his 2008 "Women for Mitt" team, Republican National Committeewoman Cindy Costa and former First Lady Ann Edwards, as are the chairs of Romney's grassroots campaign. Warren Tompkins, a senior adviser to Romney in 2008, is on Barrett's side as well, as is Romney's old finance director.
A number of top Romney donors from 2008 are also raising money for Barrett's campaign. Multiple GOP sources told CNN that Romney, who is mulling another presidential bid in 2012, did not reach out to his 2008 financial backers before heading to the Palmetto State on Thursday.
Some of Romney's former backers now supporting Barrett aren't thrilled about his endorsement of Haley. Terry Sullivan, the man who managed Romney's South Carolina campaign in 2008, even went on the record to question Romney's political influence in the state. The former Massachusetts governor finished a distant fourth in the 2008 Republican primary.
"I have a lot of respect for Gov. Romney but the fact that his biggest supporters from 2008 in South Carolina are nearly all supporting Gresham Barrett shows that his endorsement of Rep. Haley will have very little impact on her campaign," said Sullivan, who is now advising Barrett's campaign.
That sentiment was echoed by Peter Brown, a top Republican fundraiser in the state who supported Romney during the presidential race but is now backing Barrett. (Also seeking the GOP gubernatorial nomination are Attorney General Henry McMaster and Lt. Gov. Andre Bauer.)
"Mitt Romney's visit is not something that's going to change people's opinions on the governor's race," Brown told CNN. "I don't think you can count on Romney winning her three votes in the governor's race."
But Brown and other former Romney supporters were quick to point out that the endorsement is simply politics, especially in a state where political allegiances can shift with each new election cycle (and, in a state dominated by political consultants, each new paycheck). Some of Romney's 2008 supporters will likely back another candidate in 2012, even if Romney decides to run again, as a new crop of presidential hopefuls emerge and the political climate changes.
State Rep. Alan Clemmons, a co-chair of Romney's finance team in 2008 who is now on Barrett's team, said the Haley endorsement was just "political payback." He said it likely wouldn't impact who he supports in 2012.
"Haley endorsed Romney, Romney now endorses Haley," Clemmons told CNN. "I don't think there is much more to it than that to tell you the truth."
Romney spokesman Eric Fehrnstrom, traveling with the former governor during his events in Charleston, dimissed the chatter.
"There are good Republican candidates running, but Nikki Haley is a friend who has distinguished herself as a spokesperson for a new generation of conservative leadership in South Carolina," Fehrnstrom told CNN in an e-mail.
Haley's team called the comments from Barrett backers "sour grapes."
"Gov. Romney has said he endorsed Nikki because she has a proven record of conservative leadership," said Haley spokesman Tim Pearson. "Clearly, she's what he thinks is best for our state and our country. We're appreciate the endorsement, we're proud of it, and we'll stick to getting our message out to South Carolinians and leave the whining and backbiting to the political insiders who care about that kind of thing."