Outpaced by outsiders Donald Trump and Ben Carson, the one-time GOP front-runner has slashed campaign staff and costs and enlisted his family's two presidents to reassure worried donors about his White House hopes. Starting with Wednesday night's debate, his campaign is promising a sharper, more nimble and aggressive candidate and is looking to history for encouragement.
Not long before he began stripping down his campaign structure, Bush spoke about John McCain's phoenix-from-the-ashes revival in 2007, when the Arizona senator traveled on Southwest Airlines to save money and toted his own luggage.
McCain came back to win the New Hampshire primary and eventually seize the Republican nomination, a journey that underscored the fact that few establishment favorites reach the nomination without overcoming crisis and underlined the Granite State's potential for wounded establishment favorites to rescue their campaigns.
"Every winning nominee and every winning presidential candidate walks many lonely miles through the valley of the shadow of political death -- and resiliency is the chief virtue required for victory," said Steve Schmidt, a former adviser to McCain who helped engineer his comeback. "John McCain understood that, as did Barack Obama -- while going through the Rev. (Jeremiah) Wright debacle -- as did George W. Bush, after losing to John McCain in New Hampshire in 2000, and there are many other examples."
Bush will debut his relaunch at the GOP presidential debate in Colorado and in a subsequent swing through New Hampshire.
Still, even during the darkest days of their presidential bids, the three most recent Republican nominees -- McCain, Mitt Romney and George W. Bush -- did not face the kind of obstacles that loom for Bush.
Each faced a weaker field of opponents with nothing approaching the resources of a Carson or a Trump or other notable candidates such as Marco Rubio and Ted Cruz.
Bush's inevitability argument, built around the $100 million that his super PAC raised in the first half of this year, has evaporated. He is now saddled with the image of a dented front-runner who failed to drum rivals out of the race with a shock-and-awe fundraising blitz.
And the two assets that he brought to the race -- experience and political pedigree -- are no longer strengths. Bush's last name, family heritage and establishment image hardly help in a race hijacked by outsiders who have ridden a wave of deep voter disgust with the Washington status quo.
"He is trying to have a pragmatic, very practical discussion. It's not being as well-received," said Ray Tweedie, a prominent Republican Party official in New Hampshire, who pointed out that high early expectations for Bush were hurting him now. "If he is not in first place by a long shot, everybody thinks he is done. That is tough when you are fighting the narrative."
High on the list of Bush's challenges is a deficit of charisma on the campaign trail and the fact that he simply has not been able to connect with grass-roots voters, who are not buying his vision of a conservative who can fix Washington and make it work.
Tim Miller, communications director for Bush, told CNN's Wolf Blitzer on Tuesday that Bush would begin to make the argument that he's the only candidate on the GOP stage with the experience and skills to actually be president.
"What Jeb is going to do is frame this race, as ... he is the guy that can fix the problems that face D.C. D.C. is broken, it is incompetent, it is corrupt. We need someone with a proven conservative record that voters can trust," Miller said.
But that may not be the selling point it once was. In March, 57% of voters who leaned Republican told the Pew Research Center that experience and a proven record were the most important characteristic in a presidential candidate. By September, that number had shrunk to 29%.
Many of the angry, grass-roots conservatives who have flocked to Carson and Trump want to blow up the political system entirely, not make it function more effectively, raising the possibility that Bush is simply the wrong man at the wrong time.
Disinterest in Bush is a recurring theme in countless interviews with voters in early states. Mentions of his credentials and his record in Florida draw a collective shrug. Voters use phrases such as nice guy, substantive, competent, experienced -- and the deadly Trump moniker "low energy" -- to describe him.
As often as Bush vows to run "with heart" and run "joyfully," some voters also say he comes off as impatient, peevish and annoyed with the process in interviews. His attempts to show passion by aggressively hitting back against Trump as an unqualified "joke" have not produced any measurable gains.
The campaign has struggled to raise small dollar donations. And the nagging sense that voters simply do not like Bush has kept many uncommitted bundlers and big-dollar donors resolutely on the sidelines.
Often, Bush comes across as despairing at the turn the campaign has taken.
A taunting Trump stole his front-runner mantle and got under his skin. Carson has overtaken him the polls despite having no political record whatsoever. And his protégé, Marco Rubio, has jumped the line and is running against his mentor -- and ahead in the polls.
Is Jeb Bush a John McCain?
Comparisons between Bush and McCain may not be exact.
When McCain relaunched his campaign, he was able to indulge his authentic self -- as a scrappy maverick who always seeks the center of a political fight.
"McCain was a regular guy who could roll up his sleeves and sit down next to you and say 'how can I help,' " Tweedie said.
Bush, who is more of a technocrat and a less visceral political operator, will need to show he can pull a similar, loose campaign persona. On Monday, a source familiar with the Bush campaign's strategy told CNN's Jamie Gangel that Bush was now "empowered to speak his mind," promising a much stronger performance on the campaign trail.
"I think the governor has to find a way. My advice to him is ... keep your stump speech really short and let people ask questions," said Tweedie, who described Bush as one of the "best policy wonks" running and therefore a good fit with many Republicans who are beginning to drill down into detailed policy questions if he can effectively communicate his true self.
But when McCain began his long climb back riding around on the Straight Talk Express through New Hampshire and holding more than a 100 town halls, he had already built a reservoir of goodwill among New Hampshire voters who had chosen him as their candidate in an upset to George W. Bush in 2000.
Voters there already liked his brand of "straight talk" politics and his own personal story as a war hero who had been captured and imprisoned in North Vietnam during the Vietnam War.
One key piece of McCain's success, several of his former advisers noted, was that he reoriented the campaign away from the narrative about his personal ambitions to a cause -- the need, as he saw it, for a surge of troops in Iraq that would secure the national security interests of the country. He surrounded himself with veterans and went on a "No Surrender" tour drawing increasing numbers of voters to his town halls in what became a slow rebuilding of his campaign over time.
McCain turned his fortunes around, Schmidt said, by "putting a stake down -- not about 'I'm turning my campaign around' -- but 'I'm going to fight for this issue and I'm prepared to lose it all over it.' The first requirement to having a McCain-style comeback is to have a McCain-style issue that allows you to transcend the self-interest of your ambition."
Bush, meanwhile, has produced voluminous policy papers -- including the latest Tuesday on reforming the entitlement system -- but there is no one issue that seems to have struck a chord with voters.
From the beginning of the 2012 cycle, Romney faced less capable challengers than Bush, and, as it is now, the GOP electorate was splintered among a dozen GOP candidates.
Even as voters flirted with outsiders Newt Gingrich, Herman Cain and Michele Bachmann, Romney's poll numbers never slid as far as Bush's have. None of his challengers had the commanding lead that Trump, who has topped almost every national poll since July, has enjoyed. And Romney's business background at a time when GOP voters were fretting about the economy -- though it hurt him in the general election -- was more in tune with GOP voters than Bush's message is now.
And Bush's complaint over the weekend -- that there are plenty of other "cool" things he could be doing other than running for president if the job was all about thwarting progress in Washington -- could also hurt him.
The comment was revealing because it betrayed Bush's impatience with the process of running for president in the age of Trump and disdain for the circus-like aspects of the modern presidential campaign. But it also seemed to hint at a sense of entitlement from a man who has already had a tough time addressing the dynastic issue.
Bush allies insist it's too early to panic and that the race is still unsettled as many voters only now begin to tune into the race. They continue to predict a collapse of poll leaders Trump and Carson -- pointing to the flameout front-runners like Bachmann and Cain from cycles past.
"What is going to happen from now on is the real person that many people now seem to be questioning will come out," said Rep. Carlos Gonzalez, a New Hampshire state lawmaker who is backing Bush.
"He is coming in full force, you will see him come from behind and be the comeback kid," said Gonzalez,
Poll numbers offer some encouragement to those who think it's not too late for Bush.
After all, at the equivalent stage of the 2008 race, McCain languished behind Romney, and did not lead a single poll in the state until a month before voting.
On the downside for Bush however, McCain's 18% polling number was double his own, four months before the primary, showing a campaign that was already on the road to recovery -- not still mired in crisis.
Still, Neil Levesque, executive director of Saint Anselm College's Institute of Politics, also believes Bush can still be a very effective candidate if he concentrates on New Hampshire and the theme of the race turns to electability.
"I think we will see very different numbers as we get towards February 9 than we see now," Levesque said.
"I do think the state is custom-made for him," Levesque said, advising Bush to immerse himself in one-on-one interaction voters in a state which often makes its mind up late -- despite the length of its primary campaigns. "From what I see from people who go to his events is that people come away thinking 'this is a very capable man.' "