Back in early February, on the night of the Nevada Democratic caucuses, Bernie Sanders backer Ranald Adams was watching CNN while scrolling through liberal blogs like Current Affairs and Jacobin. A month earlier, Adams had decided to skip his spring semester at the University of North Carolina at Chapel Hill and drive to New Hampshire to join the legions of young volunteers knocking on doors and making phone calls for the Vermont senator. When Bernie won big, Adams says, it felt like he’d blown “a breath of fresh air into political discourse.”

Now it was ten days after that exhilaration, that glimmer of hope that, yes, Bernie could win. As he watched the results roll in from Nevada, Adams saw Sanders supporters calling foul online, claiming that the Democratic leadership had hijacked the proceedings and disqualified several dozen Sanders delegates—charges that are still hotly disputed. “If the Clinton campaign is willing to win by such measures, why should I support them?” Adams remembers thinking. At that moment, he says, he decided to vote for someone other than Clinton if she won the nomination.

Adams is hardly alone. According to a YouGov poll conducted in early May, 45 percent of Sanders supporters have no plans to vote for Clinton in the general election. The choices these voters ultimately make will go a long way toward deciding whether Clinton can rekindle the young, diverse coalition that elevated Barack Obama to victory. It’s a pressing question for Democrats: Where will the sprawling network of Sanders volunteers, activists, and coders channel their energies if Clinton, as expected, secures the nomination?

Publications from Politico to People magazine have floated the idea that some Sanders supporters will back Donald Trump in the general election. Others may gravitate toward Libertarian Gary Johnson, the former New Mexico governor who said after winning his party’s nomination last weekend that he sides with Sanders “73 percent of the time.” But laissez-faire libertarian economics won’t likely go down much better with former supporters of a democratic socialist than Trump’s white-nationalist rhetoric.

The more logical #NeverClinton option, especially for Sanders’s cadre of young idealists, has so far attracted little attention: Green Party candidate Jill Stein. The doctor and environmental activist from Massachusetts, making her second run for president, is even more of a long shot than Johnson—in 2012, she garnered just one-half of one percent of the vote. But I recently spoke with a handful of young, disaffected Sanders supporters like Adams who say they’re leaning toward Stein. They resonate with her calls to break up the banks, transition to 100-percent renewable energy, and slash military spending by half. The main factor working in Stein’s favor, though, are doubts about the sincerity of Clinton’s progressivism—and the clear itch to find a full-throated anti-establishment champion.

For Adams, the fact that Stein has no wealthy corporate donors bankrolling her campaign makes her inherently “more authentic and honest” than Clinton, who he says has spent the last 25 years courting rich donors and celebrities. “What she represents not just in the Democratic Party but in American politics as a whole is toxic,” Adams says. “I’m a single-issue voter, and that issue is corruption, campaign finance, the entire paradigm that the Clintons have driven into the Democratic Party.”

The fact that Stein has never been elected to political office makes her an even purer “outsider” than Sanders, with his quarter-century in Washington. But a vote for Stein will be, at best, a protest vote. The most successful Green Party nominee ever, Ralph Nader in 2000, won less than 3 percent—and was blamed for costing Al Gore the election by siphoning key votes in razor-tight Florida. And the only successful third-party candidates in the modern era—George Wallace, Nader, Ross Perot—have had big names and followings of their own. Stein has neither.

“Considering that somebody with much higher name recognition was able to get 2.7 percent of the vote in 2000, I think the likelihood of her doing significantly better is low,” says Micah Sifry, an expert on third party politics in the United States and author of the 2003 book Spoiling for a Fight. “She might end up with 1 percent.”

And that will raise a question for disaffected Sanders voters, once they cool off from the anger and disappointment of the primaries: If the general election is close, will they be ready to throw their vote away on a candidate like Stein, and potentially hand the presidency to Trump? Are they ready, in other words, to be the next generation of Nader voters?

Eric Wimer, a recent Columbia graduate who was involved in the “Columbia and Barnard for Bernie” student group, says he’s leaning toward Stein in November. In his view, the Democratic and Republican parties have given progressive voters an impossible choice: “Vote for the candidate who promises to keep Muslims out, or the Secretary of State with a record of bombing them and implementing policies that caused many to flee their homes in the first place? Vote for the candidate who has honestly told you he will do awful things, or the one who will tell you that she’s on your side while undermining all the ideals she claims to represent?”

Wimer’s view of Clinton seems typical of young Sanders supporters who are looking to Stein and the Green Party as an alternative. Clinton, they say, was only paying lip service to the progressive groups she courted in the Democratic primaries. “Hillary Clinton is very inconsistent,” says Maymouna Sissoko Thiam, a rising sophomore at Columbia. “She only changes her views when she sees the polling that her supporters are more growing more progressive. That’s very untrustworthy and distasteful.” And what about Clinton’s commitment to racial justice? “She just wants to get elected,” Thiam says.

“For her, it’s a show,” agrees Iliana Salazar-Dodge, a 21-year-old who plans to vote for Sanders in California primary next week and is weighing whether to switch to Stein in November. “She has to prioritize different values, different people, different corporations because of the money she receives and the connections that she has.”

While they know little about the Green Party candidate, these Sanders supporters like what they’ve seen. While Sanders has been railing about a living wage in his speeches (and Clinton has been promising a slightly more conservative increase in the minimum wage), Stein has been hitting the pavement with protesters. “Stood with striking workers this morning in Brooklyn against Verizon Wireless corporate greed,” she wrote on her Facebook page last week. Her campaign certainly has Sanders’s blend of quixotic idealism: Stein’s campaign platform, a short series of bullet points on her website called the “Power to the People Plan,” promises (without much detail) to “end poverty” and “abolish student debt.”

It’s easy to see why Stein’s echoes of Sanders are appealing to his dejected loyalists now. But come November, Sifry believes their resolve to reject Clinton will soften. “Trump will scare the hell out of a lot of Sanders supporters,” he says. “My hunch is that if the election looks close, between Clinton and Trump, that we will see very few Sanders voters avoiding that choice.”

Indeed, if you press them hard enough, some of the Sanders-Stein crowd say they might, in the end, vote for Clinton to stave off Trump. “I do support Jill Stein,” Thiam says. “But the lesser of two evils is Hillary Clinton. If it comes to that, I will vote for her in the general election.”

Wimer, like Adams, insists he’ll stick with Stein—but that’s partly because he lives in New York, a state that will likely go for Clinton in November no matter how he votes. He admits he might not vote for Stein if the stakes were different. “If I lived in a competitive state, the choice would still be very difficult,” Wimer says. “Gun to my head, it’s Clinton because of the Supreme Court, but it’s a much harder decision than it should be, considering that Trump is a lunatic.”

Salazar-Dodge is similarly torn. From a policy perspective, she ought to be an ardent supporter of the Green Party. She founded the student group in favor of divesting the Columbia endowment of its investment in fossil fuels, and she’s big on trying to “seek balance between humanity and earth.” But Salazar-Dodge is also an immigrant: She left Mexico at age four. While she dislikes and distrusts Hillary Clinton, she believes stopping Donald Trump is ultimately more important.

“I sympathize with people who do not want to vote for Clinton or Trump,” Salazar-Dodge says. “I do not think people should have to choose between their morals and what other people tell them is realistic. But I understand the math around the election. I understand that if I were to vote for Jill Stein, it could help Donald Trump win.”

Democrats have to hope that Sanders’s other young fans will, however reluctantly, come to the same conclusion between now and November. Stein offers them a clear ideological choice, much like Sanders—but the threat of a President Trump just might be enough to make them swallow hard and opt for pragmatism over principle. Just this once.