Bernie Sanders has consistently remained among the front-runners in the Democratic primary with polling that has stayed strong despite his campaign-trail heart attack last month and the rise of top rivals Elizabeth Warren and Pete Buttigieg.

But perhaps no state will test the Vermont senator’s durability more than New Hampshire, where he trounced Hillary Clinton by 22 points in 2016 and now may find himself a victim of that success since repeating such a dominate performance seems unthinkable.

Warren, a senator from Massachusetts, is trying to erode Sanders’ support among ardent progressives, while former Vice President Joe Biden continues to woo the Democratic establishment, declaring during a recent stop in the state capital, Concord: “I plan on winning New Hampshire.”

Yet another New Englander, former Massachusetts Gov. Deval Patrick, could raise the state’s stakes since he’s already relatively well known here, despite just joining the race.

And, with none of those candidates from nearby states running away with New Hampshire, Buttigieg, the mayor of South Bend, Indiana, has moved among the front-runners — similar to his rise in Iowa.

“I like what Bernie stands for,” said Jessica Pine, 42, who attended a Sanders event Saturday in Franklin and is considering voting for him, Warren or Biden. “I’m not sure about the electability for him.”

Polls in late October and early November show Biden, Warren, Sanders and Buttigieg all bunched together for the New Hampshire lead, with each seeing about the same level of support from likely primary voters.

Sanders campaign manager Faiz Shakir said in August he expected Sanders to win New Hampshire — which is expected to hold its primary on Feb. 11, eight days after Iowa’s first-in-the-nation caucuses — while insisting that falling short wouldn’t spell catastrophe.

“It gets harder if we don’t win New Hampshire for sure,” Shakir said.

Still, in September, Sanders ousted his New Hampshire state director, and a top adviser to the campaign in the state also left. On Oct. 1, Sanders had a heart attack while campaigning in Nevada.

Since then, the Sanders campaign has shown more of a New Hampshire presence and announced earlier this month that it had 90 staffers here. Warren has more than 55 staffers statewide, according to a campaign aide. And, though voters at their respective events often name Sanders or Warren as among their top choices, the senators’ campaign styles are far different.

Warren prides herself on the number of “selfies” she takes with attendees, with lines snaking throughout venues well after she’s finished speaking. Sanders sometimes moves on quickly enough that staffers begin breaking down the site moments after his event concludes — though he held a photo line of his own in Franklin on Saturday.

Warren takes questions from the audience via a lottery system. Sanders — when he does opt to take questions — is likely to pepper crowds with more questions even as he provides answers.

Sarah Gellert, a 40-year-old teacher, said she voted for Sanders during the 2016 Democratic primary but now is undecided between him and Warren.

“I feel for both candidates very deeply and I would love — of course in this la la land world — I’d love to see them on the same ticket,” Gellert said. “I’m really scared for them because they have so much overlap in terms of their voter pool.”

As he has elsewhere, Buttigieg has relied on his New Hampshire popularity rising even while still introducing himself to many voters and building out campaign infrastructure. Patrick makes the field even more crowded, but potentially helping to ease some of the logjam is California Sen. Kamala Harris, who spent weeks attracting large New Hampshire crowds only to recently close down her operations here to focus on Iowa.

In Franklin, 75-year-old Sanders supporter Lana Kangas asked the senator if in the future he would take more time to show the differences between himself and the other candidates, including Warren.

Sanders noted his age, 78 compared to Warren’s 70, experience and consistency, but answered, “I will say without hesitancy that every single Democratic candidate on his or her worst day will be 10 times better” than President Donald Trump.

After waiting to get her photo taken with Sanders, Kangas said she’s worried the other Democrats couldn’t beat Trump.

“I believe that Bernie is the only one that can galvanize the people, that will rally the people,” Kangas said. “Sen. Warren, I believe, will end up like (former President Barack) Obama. He said all the right things, he was for change, he was going to galvanize people to fight for change and when he came into office, he didn’t. It was like the whole thing got dropped.”

(AP)