For John DeButts, a 21-year-old senior at the University of New Hampshire, Bernie Sanders was a no-brainer. He was progressive. He was authentic. He was just what America needed in the White House.

But Sanders, the democratic-socialist senator from neighboring Vermont, didn’t end up winning the Democratic nomination for president this year. Hillary Clinton did. And when it comes to the former secretary of state, DeButts isn’t completely sold.

“There’s just something about her I don’t like,” he told NH Journal Wednesday. “She’s a typical career politician.”

This isn’t to say DeButts likes Republican nominee Donald Trump. The incendiary businessman repulses him. But Libertarian Gary Johnson may get this student’s vote.

“Better than those two,” DeButts said of Clinton and Trump.

This kind of thinking is a serious problem for the Democratic standard-bearer heading toward November. Polls show she’s not where she should be with Millennial voters, aged 18 to 35, and Sanders supporters are among of the biggest holdouts. The New York Times reports that “younger voters are shunning the two major political parties on a scale not seen since Ross Perot’s third-party bid for the presidency in 1992.”

On Wednesday, Clinton and Sanders descended on New Hampshire in the hopes of rectifying this situation, again swinging through the swing state where Sanders endorsed Clinton in July.

“It is imperative that we elect Hillary,” the senator told UNH, pitching the plan for debt-free college he negotiated with Clinton at the end of their primary.

For her part, Clinton said, “Bernie’s campaign energized so many young people. And there is no group of Americans who have more at stake than young Americans.”

Although Wednesday’s appearance was another show of unity, Sanders continued to acknowledge — even volunteer — that he maintains difference with Clinton.

In an interview with WMUR, Sanders said losing the nomination was difficult and Clinton has ground to make up with young voters.

“You don’t have to love the candidate,” he said in a telling moment. “What that candidate has got to do is deliver for the working class in this country. That’s what we need right now.”

There are two ways to interpret this statement, Georgetown University communication professor Leticia Bode told NH Journal: either Sanders himself isn’t that that enthusiastic about Clinton or he’s admitting that his followers aren’t. Maybe it’s a bit of both.

“He’s telling millennials, and his supporters more broadly, what he thinks they need to hear,” Bode said, “that this is a two-party system and you’ll get more done for the working class and the issues you care about if you elect one of those two parties, even if you like a third party more.”

“The question remains as to how his supporters are interpreting those statements,” she added. “In general I’ve been surprised at how die-hard some of his supporters are, though I think they are a vocal minority and most of his supporters are now supporting Clinton.”

Indeed, the vast majority of Sanders supporters have made the switch, but Clinton is worried enough to be launching a whole new millennial courtship.

She’s taking several different approaches, like poking fun at herself with Zach Galifianakis on his talk show “Between Two Ferns,” writing a Mic op-ed on what millennials have taught her and appearing on Mary J. Blige’s new Apple Music show to be serenaded with a song about police brutality. Whether or not those tactics are working, resulting in more young people seeing her as a genuine person, remains to be seen.

New Hampshire is a particular kind of swing state, including when it comes to Millennials. Democrats traditionally rely on increased minority turnout, but that strategy won’t work in a predominantly white state with one of the highest per capita incomes in the country. In New Hampshire, Clinton will need young independents to win.

Bloomberg analyzed the number of Sanders supporters in New Hampshire that Clinton needs to persuade. Among them are 35,717 independents who voted in the 2016 Democratic primary but didn’t vote in 2008. They represent eight percent of the total expected votes Clinton needs to win the state, a figure that is within the margin of most current polls between Trump and Clinton.

Of course, some of these voters won’t turn out on Election Day. Millennials are known for low turnout. And now that they’re tied with the Baby Boomer generation for the largest share of the overall electorate, it’s more important than ever for candidates to get them to the polls.

No one knows the power of Millennials better than President Barack Obama, who won the White House twice with more than 60 percent of their critical support. In a July Gallup poll, only 31 percent of young voters between the ages of 18 to 29 said they approved of Clinton.

It’s not that she’s worried young independents in New Hampshire will vote for Trump. She’s worried they’re not going to vote at all  — or vote for a third party.

“In general we see Millennials more willing to vote for third party candidates — they’re slightly more idealistic than the rest of the population,” Bode said.

At the same time, she added, “I think a lot of the support we’re seeing now will shift before Election Day, especially in swing states. I think voters are savvy enough to know that they can waste a vote on a third party in a safe state but not in a swing state.”

A recent poll by Monmouth University showed Clinton ahead of Trump by nine points in New Hampshire — 47 to 38 percent. But Johnson also took 10 percent of the vote. Some of those voters are #NeverTrump Republicans, but some are young voters like DeButts, the UNH senior, disappointed Bernie supporters.

Since Johnson didn’t make the first debate on Monday, young voters saw only Clinton and Trump. It may have helped them realize what “realistic” options they truly have, said Amy Becker, professor of communication at Loyola University of Maryland.

“I think that young people will realize [Clinton and Trump] are their only choice, and I am optimistic they’ll figure that out by Election Day,” she told NH Journal. “But I think there are a lot of young dissatisfied young people out there and [Clinton] really needs to try and appeal to the young voters.”

With less than 40 days to go, Sanders may be part of the answer to her problem, but their rally this week was their first during the general election. Aides say Sanders will be aggressively campaigning in swing states until November, but the clock is ticking.

Meanwhile, Johnson is making his case. He and his vice presidential candidate, former Massachusetts Gov. Bill Weld, also appeared at UNH Wednesday. They held a town hall-style event on MSNBC’s “Hardball” with Chris Matthews.

Several students in attendance said they can’t trust Clinton or Trump and they feel “disconnected and disappointed” in how the political process left them with two of the most unpopular candidates for president. Some were fervent Sanders supporters and said that he hasn’t “enthusiastically” endorsed Clinton, which hasn’t helped them switch their vote to her.

Bethany Balstad, 19, a sophomore at UNH, confirmed Clinton’s biggest fear.

“I know a lot of people who say they aren’t going to vote in this election,” she said.

Follow Kyle on Twitter at @kylejplantz.