US election 2012: Jon Huntsman calls for unity as he endorses Mitt Romney Mr Romney quickly responded with a tribute to his departed rival. I salute Jon Huntsman and his wife Mary Kaye. Jon ran a spirited campaign based on unity not division, and love of country. I appreciate his friendship and support," he said in a statement. Only two months ago Mr Huntsman said that Mr Romney, a former governor of Massachusetts, was "unelectable" because he lacked "core" and was "on too many sides of the issues of the day." But after seeing Mr Romney win Iowa by just eight votes, then New Hampshire by a comfortable margin, he has apparently changed his mind. Mr Huntsman was missing from the 16th debate due to be held in Myrtle Beach last night as the race whittled down to five. But his absence would scarcely have been noticed by voters in the state, who had offered only meagre support in the polls. In one survey he even placed behind the comedian and South Carolina native Stephen Colbert, who is toying with launching a satirical White House bid. Standing as a moderate conservative in a southern state where 60 per cent of Republican voters describe themselves as evangelical, Mr Huntsman struggled to gain any "bounce" from coming a respectable third in more liberal New Hampshire last week. He found the centre-Right territory already occupied by Mr Romney, who also benefited from his failed campaign in the 2008 primary which served to introduce him to the party at large. Mr Huntsman, 51, on the other hand suffered from poor name recognition, a problem that seemed to extend to the staff at his launch event in New York in June, who issued accreditation tags to the press incorrectly spelling his name as "John." Some in the party also did not trust Mr Huntsman for not only working as the President's ambassador to China for two years but for calling him a "remarkable leader" in a leaked diplomatic cable. Most of his supporters will probably support Mr Romney, which in South Carolina could make the difference between defeat and victory. However, Mr Romney might be fine without them. He leads polls in the state by an average of eight points and is the only candidate with a credible campaign structure in the states which vote over the next month. The nomination appears his to lose. The key issue after South Carolina is whether or not a single conservative challenger emerges from Rick Santorum, Rick Perry and Newt Gingrich, who are currently splitting the evangelical vote. Mr Gingrich, the former Speaker of the House, has led efforts to tackle Mr Romney, launching a series of hostile advertisements that portray him as a "Massachusetts moderate" who "can't be trusted" on abortion and other social issues. He has assaulted Mr Romney's record at Bain Capital, a corporate buy-out firm that made millions from restructuring and asset-stripping companies, sometimes laying off hundreds of workers in the process. Rick Perry, the Texas governor languishing in fifth place, routinely calls Mr Romney a "vulture capitalist."