Former Utah Gov. Jon Huntsman withdrew his bid for the Republican presidential nomination Monday, saying that the "toxic" and negative environment in the presidential race is hindering the common goal of getting a president in the White House who can reignite the economy.

Offering his support for Mitt Romney, Huntsman announced his withdrawal Monday at the Myrtle Beach Convention Center in South Carolina, where the Fox News/Wall Street Journal/South Carolina Republican Party debate was being held less than 10 hours later.

"Today, I am suspending my campaign for the presidency. I believe it is now time for our party to unite around the candidate best equipped to defeat Barack Obama. Despite our differences and the space between us on some of the issues, I believe that candidate is Gov. Mitt Romney," Huntsman said.

After several days of discussion with his family, friends and campaign advisers, the former Obama administration ambassador to China announced his suspension with a commentary on President Obama's "desire to engage in class warfare for political gain," which he said has "divided the nation more than ever."

"This divisiveness is corrosive and does not advance America's interests," he said.

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    But he called on his Republican colleagues to cease attacks on each other.

    "Rather than trying to advance our common goal, this race has degenerated into an onslaught of negative and personal attacks not worthy of the American people," Huntsman said. "At its core the Republican Party is a party of ideas, but the current toxic form of our political discourse does not help our cause and is just one of the many reasons the American people has lost trust in their leaders."

    The withdrawal immediately attracted the attention of Obama senior adviser David Axelrod, whose tweet suggested Huntsman is a bit hypocritical for backing Romney.

    "Hunts called Obama 'a remarkable leader,' Mitt 'perfectly lubricated weather vane.' Now hes 4 Mitt, and decries loss of 'trust' in politics?" Axelrod wrote.

    Prior to Huntsman's announcement, Newt Gingrich spokesman R.C. Hammond responded that his withdrawal would redound to Gingrich.

    "With Gov. Huntsman dropping out, we are one step closer to a bold Reagan conservative winning the GOP nomination," Hammond said.

    The former Utah governor placed third in last week's New Hampshire primary despite devoting most of his campaign resources to the state. He had already acknowledged that expectations for him in South Carolina's primary this week will be "very low."

    Word of the Huntsman withdrawal came on the same day The State, South Carolina's largest newspaper, endorsed him for president.

    The endorsement said there were "two sensible, experienced grownups in the race," referring to Romney and Huntsman. But it said Huntsman "is more principled, has a far more impressive resume and offers a significantly more important message."

    South Carolina senior staffers for Huntsman told Fox News they were "stunned," but partially relieved because the state had been neglected by a lack of resources and attention. Huntsman had only spent $36,000 on television ads, a pittance compared to his rivals.

    "(The) campaign never put serious resources ... to promote his serious conservative record that would have beaten Obama," Regional Southeast Political Director Adam Piper told Fox News.

    But Huntsman's own words about Romney suggested he would not be ready to endorse, and the decision also surprised many, including Romney's staff.

    Huntsman had said Romney lacked a "core," "has been on three sides of every major issue" and hadn't made an "effective case for trust in his campaign." However, Huntsman did tell Fox News that he respected Romney and thought he is a good family man and a decent person.

    Huntsman's resume suggested he could be a major contender for the GOP nomination: businessman, diplomat, governor, veteran of four presidential administrations, an expert on China and on foreign trade.

    Yet Huntsman was almost invisible in a race often dominated by Romney. One reason was timing. For months, Romney and other declared or expected-to-declare candidates drew media attention and wooed voters in early primary states. Huntsman, meanwhile, was half a world away, serving as ambassador until he resigned in late April. Nearly two more months would pass before his kickoff speech on June 22 in the shadow of the Statue of Liberty.

    To distinguish his candidacy in a crowded field, Huntsman positioned himself as a tax-cutting, budget-balancing chief executive and former business executive who could rise above partisan politics. That would prove to be a hard sell to the conservatives dominating the early voting contests, especially in an election cycle marked by bitter divisions between Republicans and Democrats and a boiling antipathy for President Barack Obama.

    Huntsman also tried to offer a different tenor, promising a campaign marked by civility. "I don't think you need to run down somebody's reputation in order to run for the office of president," he said.

    In light of his work in the Obama administration, Republicans seemed wary of Huntsman. While he cast his appointment in August 2009 as ambassador to China as answering the call to serve his country, his critics grumbled that he had, in fact, been working on behalf of the opposition.

    Huntsman was conservative in matters of taxes and the reach of the federal government, but he was out of step with most conservatives in his support of civil unions for gay couples. On matters of science, he poked fun at his skeptical rivals in a pre-debate tweet: "To be clear. I believe in evolution and trust scientists on global warming. Call me crazy."

    In the end, Huntsman didn't seem to register, crazy or otherwise, with Republicans looking for an alternative to Romney or a winner against Obama. The former Utah governor was routinely at the bottom of national polls, barely registering at 1 or 2 percent, a reflection of the faint impression he made in the GOP debates.

    His campaign put all its emphasis on the New Hampshire primary, hoping that face-to-face politicking in the first-in-the-nation primary would pay off with a strong second-place finish or a surprise victory in Romney's backyard. While other GOP candidates spent December in Iowa, the Huntsman campaign ignored its leadoff caucuses and concentrated on New Hampshire, where independents can vote along with declared party members.

    He called his third-place showing a "ticket to ride" to South Carolina, but his distant finish behind Romney and runner-up Ron Paul was widely regarded as lackluster.

    Huntsman, 51, was born in Redwood City, Calif., and raised in Utah. His father, an industrialist and at one time a Nixon administration official, founded Huntsman Chemical Corp. in 1982. Now the Huntsman Corp., it reported revenues of more than $9 billion in 2010.

    The younger Huntsman drifted a bit as a young man. He attended high school in Salt Lake City but dropped out to play keyboards in a band. He later attended the University of Utah, then dropped out to serve two years as a Mormon missionary in Taiwan, where he learned to speak Mandarin.

    He returned to the University of Utah in 1981 and later worked as an intern for Sen. Orrin Hatch, R-Utah, and as a staff assistant to President Ronald Reagan. He left college to join the Huntsman Corp. in 1983, the same year he married Mary Kaye Cooper. He studied international politics at the University of Pennsylvania, earning a bachelor's degree in 1987.

    While he served in the administrations of both George H.W. Bush -- he was ambassador to Singapore in 1992 -- and George W. Bush, Huntsman first won elective office in 2004 as Utah's governor. He was re-elected by a 3-1 margin in 2008, then resigned the following year to be America's top diplomat in China.

    Huntsman and his wife have seven children, including one adopted from India and one adopted from China. The Huntsman girls were a major force in his homegrown campaign

    The Associated Press contributed to this report.