Huntsman's path to the White House had already been fraught with difficult challenges dismal poll results, a message that didn't resonate, a lack of campaign enthusiasm and after a disappointing third-place finish in New Hampshire, where he had unleashed all his campaign resources, aides saw the ability to move on in serious doubt.
"We didn't quite get to where we wanted to be with the surge in New Hampshire, and it didn't translate enough in South Carolina," Huntsman's chief strategist, John Weaver, told The Salt Lake Tribune.
"The governor and his family and everyone for that matter after about a 48-hour discussion came to the conclusion that Romney was ultimately going to be the nominee," Weaver said. "There's not any point in staying in longer, other than for ego and that's not what Governor Huntsman is about. ... If the goal is to defeat Barack Obama, you don't want to be an instrument to obstruct" that.
The Huntsman camp sported a much sunnier disposition last June, when Obama's former ambassador to China launched his presidential push in the shadow of the Statue of Liberty. Advisers planned an ambitious three-state strategy with seven-figure budgets. TV pundits were awash in the possibility of a President Huntsman.
But the cash didn't materialize, staff shake-ups bruised his standing, and the candidate, seen as more moderate than the GOP field, found himself permanently holding down the far edges of the debate stage.
That struggle became clear last week, when Huntsman placed third in the New Hampshire primary after staking nearly all his time and effort in the Granite State. He acknowledged Monday that his campaign was the "longest of long shots."
Early on, Huntsman had refused to criticize his GOP opponents and even said at his campaign kickoff that he respected Obama.
In bowing out Monday, Huntsman called on his GOP contenders to cease attacking one another and turn their focus on explaining to voters why the GOP vision could reverse the country's economic and political problems.
"This race has degenerated into an onslaught of negative and personal attacks not worthy of the American people and not worthy of this critical time in our nation's history," 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."
Of course, that didn't mean that Huntsman and Romney always played nice on the campaign trail. The two who are distant cousins and share the same Mormon faith sparred during recent debates, and Huntsman's campaign was quick to pounce on perceived gaffes by the candidate he now backs.
Even so, Romney, sporting back-to-back victories in Iowa and New Hampshire and boasting a solid lead in South Carolina, quickly welcomed Huntsman's endorsement Monday with a salute to his former nemesis.
"Jon ran a spirited campaign based on unity, not division, and love of country," Romney said. "I appreciate his friendship and support."
The decision to pull out of the presidential race before the South Carolina runoff shocked political players but was not without warning.
Huntsman's campaign had touted it would run an aggressive ground game in the first-in-the-South primary. However, the campaign lacked the money to air ads and mount a large effort in a state where he was polling behind comedian Stephen Colbert, who grew up in Charleston, S.C.
Weaver, who had chatted with Huntsman in early 2009 about a possible presidential pursuit before the Utah governor resigned to head to Beijing, wouldn't zero in on strategy or tactics that went awry.
"I'm not going to look back at one thing that went right or went wrong," Weaver said. "At the end of the day, if you didn't win, you didn't win."
Another top aide, who spoke on condition of anonymity because he wasn't authorized to speak about behind-the-scenes discussions, said the campaign suffered from lack of funds.
"We were operating with limited resources the entire campaign," the aide said.
In addition, Huntsman didn't want to placate a certain base of the party or make outrageous statements just to cull headlines, the aide said. "The governor wasn't willing to light his hair on fire or do the soundbite that I guess gets you the attention."
As of October, Huntsman, a multimillionaire, had sunk $2.25 million of his own money into his presidential bid, mainly as loans through Zions Bank. His father, chemical magnate and billionaire Jon Huntsman Sr., reportedly also forked over more than a million for a political action committee that backed Huntsman's bid and aired ads in New Hampshire and South Carolina.
While details of how much money the Huntsmans spent won't be clear until month's end, the latest filing with the Federal Election Commission showed the campaign more than $500,000 in debt.
Still, Weaver said, no discussion took place in the past few days of the Huntsman family feeling that its time and money were wasted.
"He and the family are thrilled with the experience and what they learned and what they saw," Weaver said, "and he learned a great deal from the American people."
Huntsman aides said no discussions took place about making another presidential run in 2016 if Obama prevails but that buzz remains in political circles.
Highs and lows of Huntsman 2012
• Playing "Johnny B. Goode" on the keyboard on "The Late Show With David Letterman."
• Grabbing newspaper endorsements from The Boston Globe in Massachusetts and The State in South Carolina.
• Seeing a packed-beyond-capacity rally the night before the New Hampshire primary with the hope of a surge in the making.
• Being joined on stage in New Hampshire by his parents, Karen and Jon Sr., and most of his children.
• Seeing signs sprouting from roadsides with his name on them.
• Having his first name misspelled "John" instead of "Jon" on press passes at his June campaign kickoff overlooking the Statue of Liberty.
• Seeing private emails sent to a friend and campaign worker go public when the staffer is fired.
• Finishing third in New Hampshire after betting his entire campaign on the Granite State.
• Remaining in single digits in national polls while other rivals got their time in the spotlight.
• Sinking more than $2 million of his own money into a failed campaign