Former Utah Governor Jon Huntsman waves to supporters before announcing his candidacy for the Republican US presidential 2012 campaign at Liberty State Park in Jersey City, New Jersey June 21, 2011. [Photo/Agencies]

Former US ambassador to China Jon Huntsman on Tuesday entered the race to unseat his ex-boss, President Barack Obama, starting behind his Republican competitors in the polls but holding the potential to blossom into a strong contender.

Pledging to make hard decisions to prevent America sinking into a debt disaster, the former governor of Utah formally announced his candidacy at the same site in front of the Statue of Liberty where Ronald Reagan launched his successful first bid for the White House in 1980.

Huntsman, 51, lacks national name recognition and many polls put his support at less than 2 percent. Still, his entry into the race worries the Democratic Obama administration because of his possible cross-party appeal.

Huntsman upset the White House in April by quitting his job in Beijing to prepare to run against Obama, who appointed him in 2009.

Speaking at Liberty State Park in New Jersey as the wind whipped US flags arrayed behind him, Huntsman pledged to turn America around as president.

"For the first time in our history, we are passing down to the next generation a country that is less powerful, less compassionate, less competitive and less confident than the one we got," Huntsman said.

"This, ladies and gentlemen, is totally unacceptable and totally un-American," he told the small crowd of supporters, campaign aides and media.

Obama Campaign Responds

Obama's re-election campaign said that despite Huntsman's call for a more competitive and compassionate country, the former ambassador has endorsed a budget plan that would have the opposite effect.

"Like the other Republican candidates, instead of proposing a plan that will allow middle-class families to reclaim their economic security, Governor Huntsman is proposing a return to the failed economic policies that led us into the recession," the Obama campaign said in a statement.

Huntsman left his governorship in August 2009 with sky-high approval ratings and a reputation for fiscal conservatism but his more moderate views on social issues could make it difficult for him to win the Republican nomination.

If Huntsman gains traction, he could rival former Massachusetts Governor Mitt Romney, another Mormon, for the role of the moderate Republican candidate in a field populated by harder-line conservatives.

"We must make hard decisions that are necessary to avert disaster," Huntsman said, painting a bleak picture of the debt problem and the huge US budget deficit, due to hit $1.4 trillion this fiscal year.

"If we don't, in less than a decade, every dollar of federal revenue will go to covering the costs of Medicare, Social Security and interest payments on our debt. Meanwhile, we'll sink deeper into debt for everything else -- from national security to disaster relief."

Huntsman says his knowledge of China, America's main global commercial rival and foreign lender, is a strength but some conservative voters see his working for Obama as a liability.

Narrow Window for Victory

After the New Jersey announcement, several hundred people gathered at a Huntsman rally in Exeter in New Hampshire, an early primary state where he needs to do well.

His campaign strategy, which includes setting up campaign headquarters in the key swing state of Florida, has won him praise from campaign watchers.

"Huntsman has a very narrow window to the nomination but it's not insurmountable," said Ford O'Connell, a Republican strategist. "He has made the sell to some big donors and high powered operatives. Now he needs to make a pitch to rank-and-file Republican voters. The rank and file is where the rubber meets the road."

Huntsman promised on Tuesday to conduct his campaign "on the high road" and respect Republican rivals as well as Obama, who leads most opinion polls of the 2012 presidential race.

Among the other leading Republican candidates are former Minnesota Governor Tim Pawlenty, former House of Representatives Speaker Newt Gingrich and US Representative Michele Bachmann.

Huntsman learned to speak Mandarin Chinese while on a Mormon mission to Taiwan during his college years. He and his wife have seven children -- five biological and two adopted from Asia.

The podium for former Utah Governor Jon Huntsman is seen before he announces his candidacy for the Republican US presidential 2012 campaign at Liberty State Park in Jersey City, New Jersey June 21, 2011. [Photo/Agencies]