MANCHESTER, N.H. — The pundits think he's nearing the end. His donors are itching to jump ship. But Jeb Bush thinks he's about to take the first step toward an unlikely comeback.

"You don't have to listen to the pundits," Bush told voters here. "In fact, you'll figure it out for the pundits."

The Bush campaign enters its last day before New Hampshire votes with the single aim of delivering a top-five performance that justifies pushing south, where they say they believe a better organization and a family rescue plan will drag his candidacy up from the cellar.

And with every 2016 front-runner wounded – Donald Trump failing to beef up a sub-par ground game after an embarrassing Iowa loss, Ted Cruz looking manipulative after duping Ben Carson's supporters, and Marco Rubio's over-rehearsed debate performance feeding the robotic stereotype he spent a campaign trying to shed – Bush's team has newfound optimism, especially over the weekend as he saw the biggest crowds of his campaign here.

"Jeb's network in South Carolina is just as strong as the other three candidates who are likely to survive," said one long-time Bush donor, speaking privately. "He just has to get there."

But even with a strong organization and family network of Bush loyalists streaming into New Hampshire, it's a heavy lift. Just the mention of his name elicits laughs from Trump's crowds. His deadpan aside to a town hall last week, asking them to "please clap," exploded into an Internet meme seemingly encapsulating a fallen frontrunner's sad predicament. In interviews over the last week, reporters have been asking if he'll drop out should he do poorly here.

Bush's team would love to stun with second in New Hampshire and revive a campaign that's been written off for months. Indeed, that scale of victory might be the only thing that allays the anxieties of increasingly nervous donors, many of whom have already signaled that they'll switch their support to Rubio if Bush doesn't finish ahead of him and other establishments contenders, John Kasich and Chris Christie, on Tuesday.

"People feel like they've given him a lot of time," said one major Bush bundler based in Washington, DC, who asked to speak privately. "His issue set should be appealing in New Hampshire, so hard to make the case [to go forward] if he finishes behind those other establishment guys."

Realistically, Bush doesn't appear to be positioned for a second place finish, based on public and private polling. But his campaign is no longer convinced that he needs one.

According to people inside the campaign and sources close to it, the Bush team thinks he only needs do well enough to rationalize a trip to South Carolina, where plans for an all-out push—busing in canvassers from Florida and bringing in former President George W. Bush, already featured in a TV spot running there, to campaign—are already underway.

The strength of Bush's operation in New Hampshire belies the broader narrative of a sagging campaign. Since announcing his campaign in June, Bush has made 23 separate trips to New Hampshire. His 40 paid staffers and dozens of volunteers – more than 200 were canvassing over the weekend – have been knocking on doors and calling voters for months, even in far-flung parts of the state.

Even with what the state GOP chair has called the best ground operation of any campaign, Bush is arguably working harder than anyone else just to hold on to the roughly 10 percent of the primary electorate that's with him at the moment.

"There won't be a single candidate here who will outwork Jeb," said Jamie Burnett, a veteran of Mitt Romney's 2008 campaign here who is supporting Bush.

The voter contact efforts include calling attendees after Bush's town halls to gather feedback and gauge support, then having the same staffer follow up repeatedly by phone.

"This is an ongoing, personal conversation we've been having with voters," said Rich Killion, the operative overseeing Bush's campaign in the state. "The people of New Hampshire are deeply sophisticated; they cherish their vote and really process information and it takes them a long time."