Jon Huntsman bowed out of the presidential race in Myrtle Beach on Monday as S.C. Attorney General Alan Wilson watched with Iris and Mike Campbell, the widow and a son of former S.C. Gov. Carroll Campbell.

The former Utah governor thanked his South Carolina team for their hard work before throwing his support behind front-runner Mitt Romney. He also encouraged all the GOP presidential candidates to stop the mudslinging that has been a constant in the days leading up to Saturday's S.C. primary.

Negative ads, crafted by the various candidates' super-political action committees, currently are airing in all the state's four major media markets.

"Today, I call on each campaign to cease attacking each other," Huntsman said. "Let's invest our time and resources in building trust with the American people."

Mike Campbell, Huntman's S.C. campaign director, said he and his mother are not endorsing Romney, a former Massachusetts governor, even though Huntsman is.

Mike Campbell said he would meet with some of the other candidates later Monday and might endorse someone else.

"Obviously, Huntsman endorsing Romney has some sway with me since I trust his judgment," he said.

Others are re-evaluating.

"Gov. Huntsman's decision to withdraw from the GOP presidential campaign is not surprising, given the results in Iowa and New Hampshire, and recent polling in South Carolina," said Mark E. Lett, executive editor of The State and a member of the newspaper's editorial board, which endorsed Huntsman on Sunday.

"With Gov. Huntsman now out of the race, our editorial board will revisit the situation. Again, our interest will focus on the positions each candidate, not on who is best positioned to win or lose the nomination."

Huntsman's other prominent S.C. backers included Wilson, former state Attorney General Henry McMaster and state Sen. John Courson, R-Richland.

There was no word on whether Huntsman's S.C. political consultant, Richard Quinn, will stay out of the race or jump on board with another candidate.