Different American news media reported Sunday evening, based on sources close to his campaign, that Jon Huntsman plans to announce on Monday that he’s ending his bid for the Republican Party’s presidential nomination. The removal of content, including anti-Romney web videos, from his campaign site suggests that the former American ambassador to China intends to endorse the frontrunner for president.

Despite a better than expected third place finish in New Hampshire’s primary last week, Huntsman’s campaign struggled to appeal to right-wing voters. Although he governed as a staunch conservative in the state of Utah, where he cut taxes and reformed health care without an individual mandate as Mitt Romney did in Massachusetts, Huntsman ran as a moderate who could win independent and conservative Democrat voters in a general election.

Huntsman said climate change was real; many conservatives are skeptical of that. He supported civil unions for gay couples; a majority of Republican voters does not. His service as President Barack Obama’s ambassador to China was also deemed suspect and it was Romney who criticized him for it during the last televised debate before the New Hampshire primary.

Huntsman’s rebuttal — “This nation is divided because of attitudes like that” — won him praise and momentum in the first in the nation primary election but he still fell short of beating libertarian congressman Ron Paul for second place. Romney carried the state with a resounding 40 percent of the vote.

Huntsman’s departure from the race should enable Romney to claim the center-right vote while three of his remaining contenders vie for second place in the early primary state of South Carolina this weekend.

Former House speaker Newt Gingrich and Texas governor Rick Perry have both vehemently criticized Romney’s record as a businessman, airing television commercials that depict him as a cruel and callous capitalist while questioning the number of jobs he claims to have created as an investor. Gingrich further argues that Romney is too moderate to represent the Republican Party in November while Perry and former Pennsylvania senator Rick Santorum, who rivaled Romney for a win in Iowa’s caucuses, run as social conservatives.

Perry’s campaign is in dire straits. If the Texan fails to do well in South Carolina, which is more conservative than both New Hampshire and Florida, where the primary race moves next, he will be hard pressed to convince Republican voters that he’s a viable contender.

Gingrich’s and Perry’s attacks on Romney’s business record have not exactly improved their standing with the Republican electorate. The Wall Street Journal, a pro-business newspaper, described their tactics as “desperate.” Other conservative commentators have pointed out that their attacks are of the sort that President Obama will likely deploy against Romney in a general election. It makes their candidacies seem all the more far-fetched.

Paul and Santorum are unlikely nominees because they represent the fringes of the party. Santorum did win the support of evangelical leaders over the weekend and may yet pose a threat to Romney if he consolidates the social conservative vote. In a race against Barack Obama, however, he would all but guarantee the president’s reelection because of his strong positions on abortion, family and gay rights

Huntsman was maybe the only more electable candidate than Mitt Romney. His blend of conservative economic policy, foreign policy realism and reluctance to engage in “culture wars” could have endeared him to centrist voters who would rather vote for the president if Rick Perry or Rick Santorum is the Republican candidate.