New Hampshire is beginning to look like Jeb Bush's final stand.

Stuck in the middle of the GOP pack he was expected to dominate, Bush is accelerating the time frame for his campaign’s next ad buy in the state. His campaign also announced Tuesday that it is opening four regional field offices in New Hampshire and upping its on-the-ground staff from 12 people to 20.

That concentration of resources comes after his Right to Rise super PAC has already spent $12 million on TV ads and blanketed New Hampshire with four direct mail pieces. Bush himself has made 60 campaign appearances. Despite those efforts, polls show the former Florida governor remains mired in sixth place in the early state he most needs to win.

Now, with the state’s first in the nation primary 10 weeks away, time is running short.

“It is very fluid in New Hampshire right now, but there just doesn’t seem to be any excitement for Jeb," said Drew Cline, the long-time editorial page editor at the Union Leader who now runs a consulting business. "I wouldn’t completely rule Jeb Bush out, but I think it’s becoming clear that if he’s going to do well in New Hampshire, he has to dramatically change things and I don’t see any indication that that’s happening."

Bush’s team continues to insist its organizational strength will matter more in the end -- and is more relevant than the polls. Bush has also campaigned in the state far more often than recently ascendant rivals Ted Cruz and Marco Rubio.

“Rubio is not here very much at all. He has better poll numbers, but we have to see if that can be sustained,” said one New Hampshire-based political operative. “If Jeb can beat expectations, which shouldn’t be that hard these days, he might have a path out of here.”

Bush, whose campaign just completed a month-long run of ads in the state, hadn’t planned to go back on the air until January. But in a sign of the urgency of his predicament, the campaign announced it has reserved three weeks of airtime starting this week, in the hopes of securing a top three finish on Feb. 9.

“I think that’s indicative of a realization on their part that they can’t wait until late in the process," Cline said. “Not only is he not the only plausible candidate like Romney was in 2012, he’s not your default or backup. Primaries are about performance, and he is not performing.”

Should Bush lose badly in Iowa and fail to finish in the top three in New Hampshire, his bid for the GOP nomination would likely be all but finished before the race heads to South Carolina.

The new $600,000 ad buy from Bush’s campaign coincides with a run of ads from his Right to Rise super PAC, which is spending $1.5 million to blanket the airwaves this week.

The campaign is going up with 30- and 60-second versions of a new ad featuring a number of Medal of Honor winners extolling the virtues that they believe would make Bush a strong commander in chief.

“This nation hungers for leadership,” say Col. Jay Vargas, a retired Marine and Medal of Honor winner, in the ad. “We need Jeb Bush.”

Bush's new spending flurry comes as the former Florida governor battles for the support of moderate to conservative establishment Republicans, currently scattered to a number of rivals. Rob Thomson, the son of former Gov. Meldrim Thomson and a veteran of George W. Bush's 2000 campaign in New Hampshire, recently threw his support behind Rubio. Doug Scamman, a former New Hampshire House speaker, and his wife, Stella, went with John Kasich.

"I think 50-60 percent of Republicans here agree Jeb’s just not the right guy for this cycle," said Fergus Cullen, a former state GOP chairman. "I know they concluded they like Jeb; they just don’t think the country’s going to go for another Bush next year."

Bush's struggles have left the door open for Chris Christie, the New Jersey governor whose focus on New Hampshire may be starting to bear fruit.

Although Bush has refocused his campaign on national security in the aftermath of the ISIL-coordinated terrorist attacks in Paris last month, he has yet to move the dial in a significant way. Christie, however, who speaks forcefully about his experience in New York City on 9/11 and outlined his own plan of attack against ISIL last week during a speech to the Council on Foreign Relations, appears to be getting a second look from some.

Over the weekend, the New Hampshire Union Leader, the state’s biggest newspaper, endorsed Christie, who until now struggled to convince voters of his viability in the GOP race. On Monday, Christie followed that up by winning the much-coveted endorsement of Renee Plummer, a prominent Seacoast GOP activist; a day later, Donna Sytek, a former state House Speaker, also announced her support for Christie.

“It wasn’t so much anything that [Bush] did wrong; it’s just looking back at Christie legacy in New Jersey,” said Plummer, who acknowledged Tuesday a strain of fatigue with the family brand is working against Bush. “ I loved 41, I loved 43 and I really like Jeb. But I don’t know how America is going to respond to another Bush.”

As Plummer announced her intentions Monday, Bush was suffering another indignity — criticism from 2012 flash in the pan Herman Cain, who’d taken umbrage at Bush for citing Cain's short stint atop the primary polls four years ago to argue that the 2016 race remains fluid and the polls unreliable.

“If you want to say I had a ‘fall,’ go ahead, I guess,” Cain said Monday. “You can’t fall when you’ve never gotten any higher than the floor in the first place, and that’s the state of the Jeb Bush campaign.”

Still, Bush’s New Hampshire team is counting on voters there following form and deciding late. But while many people remain undecided, the opinions of some activists have hardened toward Bush, due largely to his unmemorable performances in the first few debates.

“Jeb was on my list. I had seen Jeb a couple of times up here and I kind of liked what he had to say, but it was the debates where he showed a lack of passion that I’ve seen in other people,” said Jody Nelson, the vice chair of the Derry GOP, who decided to support Marco Rubio following the Oct. 28 debate where Bush's attempt to attack his former protégé backfired.

“I think he had a chance if people felt really strongly about him, but people don’t feel really strongly toward him,” Nelson continued. “In the last debate, even though I’m supporting Rubio, I was sort of rooting for Jeb to do better, like: ‘You can do it, Jeb!’

“I don’t know. It was painful. And I don’t know what he can do to get it back.”