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Jon Huntsman Jr. is a high school dropout, a Harley-riding ex-governor and a diplomat whose last boss was President Barack Obama. Now this Republican wants Obama's job.

The unusual political resume and sometimes centrist views makes Huntsman both a long shot to emerge with the GOP presidential nomination and a candidate to be feared by the Democrat in the White House should he break out of the pack.

At the Tacos Don Rafa food cart in downtown Salt Lake City, though, Huntsman is known simply as a regular, often dressed in a denim jacket.

"His palate can withstand more hot sauce than anyone else I've met," says Rep. Jason Chaffetz, R-Utah, Huntsman's first chief of staff. "I think that's why he liked the taco carts, because of their authenticity."

Authenticity also defines Huntsman, friends say, and helps explain his success as a moderate politician in solidly conservative Utah, where he was re-elected with 75 percent of the vote in 2008. Huntsman resigned from the governor's mansion less than a year later when Obama tapped him to serve as his ambassador to China. He gave up the diplomatic post in Beijing after less than two years to make his run for president.

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He entered the GOP presidential field on Tuesday, flanked by his family and with the Statue of Liberty as a backdrop.

Huntsman's moderate views could work against him in the Republican primaries, where conservative voters dominate. As Utah governor, he supported legislation to deal with climate change and backed civil unions for gay couples, positions that angered the GOP base but had little impact on his overall popularity.

"It makes him an incredibly weak candidate in the GOP field," says Alex Slater, a Democratic consultant. But if Huntsman can win the Republican nomination, Slater says, he would be "the only candidate the White House fears" in a general election.

Huntsman, 51, is certain to face questions for his time working for a Democratic president. That "cardinal sin" of tea party politics may be enough to scare Republican voters back to traditional candidates, says Democratic consultant Mo Elleithee, who worked on Hillary Rodham Clinton's 2008 presidential campaign.

"The people who do the best in the GOP primaries are the most conservative or the most establishment," Elleithee said. "He is neither of those."

The little-known Huntsman — he ranks in the single digits in public opinion polls — has never been traditional or establishment.

While he's the namesake of a billionaire businessman and a member of one of the most prominent families within The Church of Jesus Christ of Latter-day Saints, he's also a high school dropout who spent the latter part of his teen years playing with local jazz and rock bands.

Those years ended when he briefly enrolled at the University of Utah through a program that granted him admission without a high school diploma. He then went on a Mormon mission to Taiwan, where he learned to speak Mandarin.

He later attended the University of Pennsylvania and graduated with a degree in political science, then entered public service and eventually worked for Presidents Ronald Reagan and George H.W. Bush.

In 1993, after leaving his post as ambassador to Singapore, Huntsman became president of the Huntsman Cancer Foundation and eventually CEO of Huntsman Family Holdings, the umbrella company for the multibillion-dollar corporation founded by his father.

Huntsman first ran for Utah governor in 2004, winning with 57 percent of the vote. .

As governor, proposals to significantly boost education spending and a repeal of the tax on food garnered him support from moderate members of both parties. In the 2008 campaign, the most effective argument that Democrats could muster was that Huntsman was unlikely to serve his full second term, and they were right.

Senators lavished so much praise on him during his confirmation hearing for the ambassador's job that Huntsman said he hoped to fare as well at his funeral. Taking up his post in Beijing amid sometimes unsteady U.S.-China relations, Huntsman prodded the Chinese on human rights and worked to expand U.S. engagement with the growing economic powerhouse.

Democrats may have thought that putting Huntsman to work for Obama effectively took him out of the 2012 political equation, but that appears to have been a flawed assumption.

"I'm sure that him having worked so well for me will be a great asset in any Republican primary," Obama said with a laugh when Huntsman submitted his resignation.

Despite being a Mormon Republican from Utah, a factor that hurt fellow Mormon and part-time Utah resident Mitt Romney in his 2008 bid for the GOP presidential nomination, Huntsman could be the most moderate GOP politician in the crowded field for 2012.

"He infuriated those who tried to hijack the party, those who claimed to speak for God," said University of Washington President Michael Young, a friend since they served together in the first Bush administration, when Huntsman was a deputy trade ambassador. "But he was wildly popular with the bulk of the party."

Friends and colleagues describe a man who puts a priority on family.

Sen. John McCain, R-Ariz., one of Huntsman's closest political allies and a good friend, points to the results: two sons in the U.S. Naval Academy, a concert pianist daughter and another daughter who works for a New York City public relations firm. Huntsman and his wife, Mary Kaye, have seven children in all, one daughter adopted from China and another from India.

"It comes from being a tight-knit family," McCain said.

Utah Gov. Gary Herbert, who was Huntsman's lieutenant governor, says GOP primary voters may be impressed enough by Huntsman's fiscally conservative principles to overlook any perceived negatives.

After all, he supported school tuition vouchers, pushed through a mostly-flat income tax and backed a state constitutional amendment banning gay marriage in 2004.

What strikes Herbert most about Huntsman is his lack of pretense.

"He could have chosen the lifestyle of the leisurely rich, but instead he put himself into service," Herbert said. "He is down to earth."