Democratic presidential candidate Hillary Clinton meets with voters at Manchester Community College during a rally Monday, the day before the New Hampshire primary. (Melina Mara/The Washington Post)

Trailing Sen. Bernie Sanders among nearly every demographic group in New Hampshire, Hillary Clinton spent her final days here trying to stanch the bleeding in one key group — young voters, whose exodus spells particular trouble for the Democratic front-runner far past Tuesday’s primary.

On the heels of the narrowest of victories in Iowa, aides say Clinton was genuinely shocked to learn that nowhere is her deficit with Democrats greater than with young voters, whom she lost by a whopping 70 points.

A new CNN/WMUR poll for New Hampshire foretells worse. Among likely Democratic voters between ages 18 and 24, Sanders leads Clinton 85 percent to 10 percent. The 74-year-old independent Vermont senator is 30 points ahead of Clinton, who is 68, among voters ages 35 to 49. The poll released Sunday showed Clinton and Sanders tied at 49 percent among voters ages 50 to 64. Only among voters 65 and older does Clinton win outright, 51 percent to 42 percent.

Campaigning for his wife Monday, former president Bill Clinton urged supporters to “go out there and talk to young people. She’d be way better for them.”

“Want to get good college aid? Want to get good jobs?” he continued. “Want to get health care quicker — and keep it longer? We’ve got to move this country from anger to answers.”

Clinton remains the favorite for the Democratic nomination, based largely on her popularity with middle-aged, middle-income voters, as well as African Americans and Hispanics who are concentrated in states that vote after heavily white Iowa and New Hampshire.

“We have the makings of a winning coalition with those already supporting her, but we know we have room to grow, and we want to keep reaching out,” Clinton’s press secretary Brian Fallon said in an interview.

A forum at a small college campus here over the weekend suggested the beginnings of a reboot of Clinton’s strategy to stem her losses among the young. Although Americans younger than 30 typically vote in low numbers, the energy and momentum of Sanders’s insurgent campaign is drawing more young people into the political process. Clinton’s aides know many of those voters will remain engaged as the political calendar moves to friendlier states for her.

“A lot of young people in New Hampshire may not be for her, but they are the next generation,” said Jennifer Palmieri, Clinton’s communications director. “She’s not going to turn people in one session, but she wants to hear from them. They are the next generation and they are really engaged. She wants them to understand her better.”

So, at Clinton’s direction, her aides advertised a question-and-answer session at New England College. They advertised the event on a local “Students for Sanders” Reddit page.

“Bernie supporters are more than welcome,” the message read.

A moderator of the online bulletin board chimed in: “They’re not trying to cause any trouble here.”

Clinton chucked her wonky stump speech and told the crowd, mostly students and young adults, that she welcomed questions from those supporting Sanders or still trying to decide.

The questions were tougher and Clinton’s answers less scripted than her usual town hall-style sessions with voters. She was asked about her trustworthiness, the controversies flowing from the Benghazi attacks and her use of a private email system as secretary of state. She was asked why she comes off as stiff and programmed.

Sanders’s iconoclastic appeal was the main theme underlying many questions. Clinton said she understands it and sees parallels to her own political awakening as a volunteer for long-shot antiwar presidential candidate Eugene McCarthy in 1968. Left unsaid was that Clinton was once idealistic too, but McCarthy, like Sanders, mobilized young supporters with his unapologetically liberal message — and he lost.

“I am really happy to see so many young people involved in the political process, I really am,” she said.

“I know that Senator Sanders has a very big base of younger voters, and they’re not supporting me,” Clinton said. “I’m going to do everything I can to fix these problems, like debt in college and making college affordable, and that’s the way it should be,” she said.

She added that she won’t promise free college on the government dime, as Sanders does, because it would not solve the underlying problem of skyrocketing tuition.

It was unclear that the freewheeling 90-minute session changed any minds. Her campaign aides said they cannot be sure how many Sanders supporters came as a result of the unusual invitation posted on a forum that has become a hub for Sanders organizing — and for occasional vitriolic and sexist anti-Clinton rants.

“There was a healthy number of Bernie stickers” among the crowd, Clinton chief digital strategist Teddy Goff said in an interview. “Which was the point.”

The window of opportunity to reach Sanders supporters here is narrow. The campaign believes it has a chance by focusing on voters who love him and don’t loathe her.

Her campaign aides here say they recognize that New Hampshire voters are hesitant to hand Clinton an easy primary victory and are eager to extend Sanders’s time in the game, as is their early-state prerogative.

“I sort of like him,” a woman in her 60s said to a 19-year-old Clinton volunteer, Emily Rice, who came knocking on her Manchester door Sunday. “It’s embarrassing,” the woman said of her own indecision. “We’re voting in two days.”

Rice, a sophomore at St. Anselm College, said that among women her age, “it’s more of a movement they’re swept up in.”

When the young woman at New England College asked Clinton why she is perceived as “rehearsed,” Clinton sighed, smiled and dove in.

Sanders, wild-haired and passionate, has a cool factor she may not possess, Clinton acknowledged. But she has a higher goal than cool, she suggested, and better qualifications for the job.

“I do have a somewhat narrower path that I have tried to walk,” she said. “It comes across as a little more restrained, a little more careful, and I’m sure that’s true — which is why I love doing sessions like this.”

In New Hampshire, the campaign is racing to shore up gettable, undecided voters: older women and registered Democrats who overwhelmingly support President Obama and are likely to be more open to Clinton’s message of continuity. Sanders remains the strong favorite among New Hampshire voters registered as “undeclared,” who can vote in the Republican or Democratic primary.

The Clinton campaign is focusing its organizing effort here on turning out committed voters on primary day and drawing uncommitted people to Clinton events. With limited time available, Clinton has focused on Democratic population centers such as Manchester, Concord, Nashua and Portsmouth. And unannounced visits to coffee shops and local establishments drum up buzz in local media and online, a critical part of the effort to stretch the campaign’s reach to as many corners of the state as possible.

“Here’s the thing about New Hampshire: The last time in 2008, I went back and looked at this — 48 percent of voters in New Hampshire said they made up their mind in the last week,” said Clinton’s chief pollster and adviser Joel Benenson. “This is a state that is the most independent state in the country, both politically and, I think, culturally.”

At a breakfast sponsored by the Wall Street Journal, Benenson said, “You know the whole Live Free or Die model? This is a real part of the ethos here.”