HUDSON, N.H. – Karen Forleo thinks it would be a debacle if Democrats nominate Bernie Sanders. On the eve of the New Hampshire primary, the retired dental hygienist remains undecided between four of his rivals. She loves Pete Buttigieg’s youthful vigor, Joe Biden’s experience, Elizabeth Warren’s plans and Amy Klobuchar’s grit. But the 62-year-old isn’t sure who is the best bet to stop Sanders.

“I know he appeases the young students who have no money. Well, somebody has to pay for everything he wants,” Forleo said Sunday night after watching Biden speak for 90 minutes in a high school gymnasium here. She plans to attend rallies this afternoon for Klobuchar in Exeter and Warren in Portsmouth.

The Democrat from Lyndeborough, who supported Hillary Clinton in the 2016 primary, remains frustrated that Sanders didn’t do more to help her that fall. “If Bernie leads the ticket, I don’t think the American people are going to be ready for that. I don’t think he can beat Donald Trump,” she said. “And if Donald Trump thought he could, Trump would be all over him like he is with Joe Biden.”

The splintering among moderates like Forleo is an important part of the explanation for why Sanders, the independent senator from neighboring Vermont, is the favorite to win Tuesday’s contest. There’s a very fluid and incredibly tight three-way battle for third place.

Buttigieg has surged since the Iowa caucuses a week ago into a solid second-place position, prompting attacks from all directions that appear to have slowed his momentum a bit.

Biden has been tanking in the polls since finishing fourth in Iowa, prompting many people who had planned to vote for him because they perceived him as the most electable option to check out others. Klobuchar has been rising. She drew her biggest crowds of the campaign this weekend and reporting her best fundraising days yet after Friday night’s debate.

Warren, who represents neighboring Massachusetts and led in polls of this state last summer, seems to be losing altitude here on the ground, even though she finished ahead of Klobuchar in Iowa. About a third of the people at her rally at a middle school in Concord on Sunday afternoon streamed out before she finished talking.

A brew of other factors is also working to Sanders’ advantage on the eve of the first-in-the-nation primary. Most Democrats don’t want Sanders to be their nominee, but they cannot agree on who to rally behind instead. Despite rumbling concerns of the establishment, there’s no organized Stop Sanders or Never Bernie movement. In fact, Democrats who don’t support Sanders still hold largely favorable views of him. Unlike in Iowa, where he faced nearly a million dollars in attack ads, no one is on the air here with anti-Sanders commercials.

Sanders expanded his lead Sunday night in the final day of the Boston Globe-WBZ-Suffolktracking poll. He garnered 27% among likely Democratic presidential primary voters, up from 24 to 25% in the previous six polls. Buttigieg, who briefly eclipsed Sanders in the poll one day last week, got 19% in the latest survey, followed by Klobuchar at 14%. Biden and Warren tied at 12 points. The margin of error is plus or minus 4.4%.

You should take all the polling with a grain of salt because this contest is so in flux, but two other surveys published Sunday also showcased Sanders’ relative strength among likely voters. A University of New Hampshire poll for CNN put Sanders at 28%, with Buttigieg at 21%, Biden at 12% and everyone else in single digits. Buttigieg led among voters who identify themselves as moderate or conservative, while Sanders led by more than 25 points among self-identified liberals. Asked whom they expect to win, regardless of whom they’re supporting, 57% in the CNN picked Sanders. Interestingly, Sanders also took a seven-point lead over Biden on the question of which candidate has the best chance to defeat Trump in November, a reversal since Iowa.

A YouGov poll for CBS pegged Sanders at 29%, up two points compared to last month, with Buttigieg at 25%. Most of Buttigieg’s double-digit gains in that survey come at the expense of Biden, who fell to 12%, trailing Warren. Only 39% of likely voters in the CBS poll said they’ve definitely made their final decision, and only six in 10 said they’re enthusiastic about the candidate they’re leaning toward. Sanders’ supporters were the most enthusiastic.

They compete for different kinds of voters, but Sanders has been attacking Buttigieg partly out of a desire to prevent him from coalescing moderate support and thereby overtaking him in this must-win state.

Sanders could benefit from a similar dynamic to what allowed Trump to amass an unsurpassable delegate led during the 2016 Republican primaries, even as most GOP voters opposed him. The odds, at least initially, are that all the top contenders will stay in the race beyond New Hampshire, continuing to divide up support going into the next two early states. Mike Bloomberg is waiting in the wings, spending literally hundreds of millions of dollars in states that vote on March 3, also known as Super Tuesday, when a third of all pledged delegates to the convention are awarded.

Four years ago, Sanders struggled with nonwhite voters and hit a wall because of Latinos in Nevada and African Americans in South Carolina, the next two states to vote. The senator has worked hard to make inroads with communities of color ever since, and Biden’s fade could boost Sanders in the Palmetto State by dividing up the black vote.

The Sanders campaign, which has invested heavily in organization, said that volunteers knocked on more than 150,000 doors on Saturday alone. Sanders’ field program is focused more on mobilization of known supporters than persuasion of the undecided, a contrast to the late-surging campaigns like Klobuchar’s and Buttigieg’s who are still trying to identify potential backers. The campaign said 1,981 people attended Sanders’ rally last night in Keene. Rep. Alexandria Ocasio-Cortez, D-N.Y., will join Sanders on Monday night for a massive concert the campaign is putting on in Durham, home to the University of New Hampshire, featuring The Strokes and Sunflower Bean.

The Sanders campaign slogan is “Us, not me.” But his stump speech increasingly sounds like “Us versus Them.” And the “Them” is the party establishment. He’s added a little more pitchfork to his populist tone in the recent days. “We’re taking on not only the whole Republican political establishment and Trump,” Sanders said this weekend. “We’re taking on the Democratic establishment.” His supporters from four years ago remain angry at the system and feel let down by both parties. The undercurrent of anti-elite frustration that helped propel Trump still exists in 2020, despite strong top-line economic indicators.

Nick Landry, 27 of Somersworth, said he has tried hard to keep an open mind since supporting Sanders four years ago. He considered Warren “very strongly.” He heard out entrepreneur Andrew Yang, who was intriguing, but he found his plan to give everyone a thousand bucks a month “kind of gimmicky.” After watching the Democratic debate on Friday night, he decided he’ll probably back Sanders again.

“We lost in 2016 by trying to play to the middle. As a liberal, I believe we should swing for the fences. And if we’re not going to win, let’s at least go down pushing for progressive ideals,” Landry said at a Sanders rally in the packed-to-capacity Opera House in Rochester. “Biden represents the establishment, and I think Pete and Amy are part of the establishment.”

The data analyst for an insurance company supports Medicare-for-all and badly wants stricter gun laws so that his kids will be safer at school. Landry said he totally understands why some Democrats fixate on electability, but he said Trump and Senate Republicans have shown themselves to be such “cartoonish villains” that he doesn’t believe the opposition should pander to win back the kinds of voters who supported Barack Obama in 2012 but Trump in 2016. “They’re keeping kids in cages,” Landry said. “I don’t want to necessarily be shaping our political platform around trying to appeal to people who aren’t bothered by that.”

Meanwhile, moderate voters express growing concern about what they see as a collective action problem. Siobhan Brace, 62, was the first person to ask Biden a question during his town hall meeting on Sunday night. “I love you a lot, but I am undecided,” she said. “I thought everybody did a great job in the debate, but I am afraid of that one of you cannot beat [Trump], but I think all of you could. Is there some way that you guys could put a dream team together and present that to the American people? And just say, like, Amy is going to be vice president and we’ll put Andrew [Yang] in charge of Commerce?”

The crowd cheered. Biden laughed. “There’s two ways to be on the dream team: run it or be picked,” he replied. “I promise that you my administration will look like the country. It will be made up of women and blacks and browns and people who represent the diversity of the country. There are at least six women I can think of at the top of my head who I wouldn’t have a moment’s hesitation in asking to be my vice president. I can say the same thing for at least four leading African Americans that I know.”

Reflecting the degree to which voters still believe he’s in contention, Biden was asked again half an hour later who he might pick for vice president. Biden said he didn’t want to be presumptuous, but then he hinted that he might select Buttigieg. The 77-year-old said he could promise that he would not pick anyone who is older than him to be his No. 2, which would take out the 78-year-old Sanders. Biden added that he cannot imagine picking someone to be vice president who supports Medicare-for-all, a knock against Sanders. “But there are at least four people running that are, in fact, simpatico with where I am, starting with Indiana,” he said, a reference to Buttigieg, the former mayor of South Bend, Ind.

Brace, who asked the first question to Biden, said in an interview afterward that she’s “terrified” Trump will win. “Bernie’s too way over there,” she said, pointing with her left arm to the other side of the room. “The Republicans that are on the fence are going to come with a moderate. We need to get some of the Republicans who do know that Trump is crazy to come over to our side, and they’re only going to do it with a moderate. So we’ve got to find a moderate.”

Independents could have outsized influence in tomorrow’s open Democratic primary because there’s not a competitive race on the Republican side. Though Trump is flying up here to hold a rally in Manchester tonight, he faces no competitive GOP primary. Polls show the incumbent president getting more than 90% against former Massachusetts governor William Weld. New Hampshire has 416,000 “unaffiliated” voters, who get to pick which primary to participate in.

Sanders defeated Clinton by 22 points in New Hampshire four years ago, garnering 60%, or 152,000 votes. Polls and interviews make clear that most of the people who backed him as the anti-Clinton candidate four years ago will not support him again this time. That said, I encountered a few people at the Sanders rally in Rochester who backed Clinton in the primary four years ago and are giving Sanders a close look.

“We need grass-roots change, and it may be more than some of the traditional establishment is willing to go, unfortunately,” said Colleen Hartnett, 57, of Windham, a software engineer who remains undecided. “I think I’m leaning more toward the progressive side rather than the moderate part of the party at this point. . . . Because Republicans have gone so far, the contrast is just striking. I feel like the pendulum can’t just go for a moderate swing.”

Sanders knows he needs to win this neighboring state, which is why he doesn’t hesitate to confidently predict victory. There’s no apparent effort to manage expectations. “I am absolutely confident that, with the volunteer support we have, we are going to win in New Hampshire,” Sanders said Saturday night in Manchester. He said his 2016 victory in New Hampshire was critical to winning 22 more states in the months that followed, and he said winning the primary helped put some of his ideas that were called radical four years ago into the mainstream. “We need to complete the revolution we started four years ago in New Hampshire,” he said.

Warren losing altitude in New Hampshire also likely works to Sanders’ advantage. She drew only a modest crowd Sunday afternoon to a middle school near the state capitol. “Our democracy hangs in the balance, and it is up to you, Massachusetts, to decide what to do,” she said at the end of her speech, after more than a hundred people had left, many to go watch other candidates.

“New Hampshire,” people in the audience yelled.

“And to the people of New Hampshire,” she added, correcting herself with a laugh.

The crowd applauded. “Thank you,” she said, appreciatively. “It is a hard time.”

Warren brushed aside a question afterward about the people who left, calling it an “enthusiastic” crowd. “It looks like it is going to be a long battle to the nomination,” she told reporters. “There are 55 more states and territories after this. . . . I’m in it for the long haul.”

Other candidates who struggle to get covered are trying more colorfully to contrast themselves with Sanders. James Carville, the Democratic strategist who helped elect Bill Clinton in 1992, stumped late Saturday afternoon for Sen. Michael Bennet, D-Colo., in Manchester. He emphasized that Sanders would be a problem for down-ballot Democrats, especially in competitive Senate and House races. “They’ll run away from Bernie Sanders like the devil running away from holy water,” Carville said. “If Michael Bennet is the nominee, Mitch McConnell’s going to look like he crapped a pineapple.”