Soon and very soon, Bernie Sanders is going to have to help his most ardent fans confront the fact of his defeat. How he does so will help to determine his legacy.

That is not meant to disparage the campaign or the candidate, despite the vitriol that’s sure to start flooding into my Twitter timeline right now. It’s a statement of mathematical fact. As of today, no matter what happens in Kentucky (or Oregon, or Puerto Rico, the Virgin Islands, Montana, New Jersey, New Mexico, North Dakota, South Dakota, Washington, D.C. or even mighty California), Hillary Clinton is going to be the Democratic nominee.

Clinton is 94 percent of the way to the 2,383 required delegates, having won 54 percent of the total pledged delegates so far, to Sanders’s 46 percent. She needs only 35 percent of what’s left, while Sanders needs 65 percent, and a literal miracle. If you throw in superdelegates, as they stand today, Clinton needs just 14 percent of the remainder to win, versus an astounding 86 percent haul Sanders needs.

Everyone covering this race knows these facts, and the only question is how to manage the communication of them in a way that respects the ongoing democratic process.

Of course, none of that has stopped the magical thinking, and in some quarters, the rage and even conspiracy theorizing of hardcore Sandernistas who refuse to accept that the war is lost. Case in point, the cantankerous Nevada Democratic convention in Las Vegas this weekend at which stalwart liberal California Sen. Barbara Boxer was booed and shouted down for the crime of calling for civility and party unity, and a fight literally broke out on the convention floor over the setting of rules and the election of 43 delegates and three alternates to go to the July 25 national convention in Philadelphia.

Indeed, there’s nothing quite like firing up Twitter only to be inundated by Bernie-hair avatars shrieking about hundreds of thousands—no, millions—of would-be Bernie voters falling victim to a supposed national voter suppression campaign that is the “real reason” he isn’t winning. The culprits, in this alternate reality, are the Democratic National Committee, which does not set the rules for individual caucuses and primaries. They are run, respectively, by state parties and state legislatures, but according to the theory, they’ve been gamed by nefarious Hillary Clinton operatives in the parties, who have been programmed by “The Establishment” to deny Bernie his rightful nomination.

And then there’s Sanders, his wife Jane’s and some of his prominent surrogates’ dismissals of the heavily African-American Southern primaries won by Hillary Clinton as irrelevant red states that are too conservative, too “brand loyal” and too unacquainted with their own best interests to have voted the “right way”; nearly all-white red caucus states like Idaho, Utah, Wyoming and nearly all-white, red primary states like West Virginia notwithstanding.

The rush to conspiracy theories, appropriation of the real, ongoing struggles against actual voter suppression including voter ID laws, and the embrace by some on the Sanders left of every scurrilous accusation against Hillary Clinton, from the ’90s to Benghazi, is jarring. And the memes are especially vicious among the youngest Sandernistas, whose abject, #BerntheWitch hatred of Secretary Clinton is reaching World Net Daily proportions. In fact, some supposed leftists have taken to tweeting out actual WND, Breitbart, and Daily Caller links to prove their case.

And while this likely represents a small minority of Sanders supporters, much like the Hillary PUMAs and “Obama bros” in 2008, the Sanders campaign and the candidate have done little to try to shut it down.

In 2008, Team Obama pushed out foreign policy adviser Samantha Power and sidelined Obama national co-chair Rep. Jesse Jackson Jr. for slagging Hillary Clinton as a “monster” and mocking her New Hampshire tears, respectively. Obama himself directed his team and supporters to lay off the Clintons, while the Clinton campaign ultimately forced out Geraldine Ferraro over her racial bitterness, and wouldn’t let the PUMA faithful anywhere near the Denver convention, to the point where some of them turned on Hillary herself as a traitor to the cause.

By contrast, Sanders and his team have seemed at times to encourage the bitter-enders to fight to the proverbial death, with the campaign itself vowing to contest the nomination right onto the convention floor. It’s not clear what Team Sanders hopes to achieve, beyond a platform battle in Philadelphia that will make for a great TV spectacle, but won’t change the outcome.

Meanwhile, a reality show vulgarian with a penchant for fight club rallies, tasteless broadsides against “flat-chested women” and a singular ability to excite white nationalists (including his own longtime butler) with his anti-Muslim and anti-Mexican rhetoric is quickly consolidating the Republican Party behind his nomination. And some Democratic operatives are starting to worry that Sanders’s zombie campaign is preventing Hillary Clinton—who possesses some real flaws as a candidate, from her inability to deliver a big speech to the ongoing drag from her paid speeches and her private email server—from focusing her full attention and resources on the real target.

If Sanders does hope to have a future in Democratic Party politics, he will eventually have to tell his supporters the truth: that he simply lost the primary contest, despite a hard-fought race. He’ll have to walk back some of his sharpest anti-Clinton rhetoric, and find some way to become a bridge to the voters who have become so fervently devoted to him.

It’s tough to imagine the Vermont senator actively embracing Clinton, who is considerably more hawkish on foreign policy, and less ambitious on domestic affairs than he. But Sanders has a particular credibility with white working-class voters and young, mostly white collegians. Sanders’s particular resonance with the white working-class,a group that has bedeviled Democrats over the last 50 years, and whose skepticism of free trade makes them a prime target for Donald Trump, could prove to be his most valuable asset to his newfound party. Sanders has proven to be an effective attacker when he sets his mind to it. If, as he says, he wants to do everything in his power to prevent a Trump presidency, nothing is preventing him from using his capital now, to try to prevent those voters in his camp from bolting to Trumpville by training his fire on the Republican nominee.

Of course, Sanders could refuse to do that, perhaps concluding that he would lose too much credibility with the rather angry movement he’s built, and go right on hitting Hillary Clinton instead. But he risks winding up an isolated figure in Philadelphia, surrounded by his diehards but scorned by Democrats who blame him for weakening the nominee, tolerated by Camp Clinton only because they have to, and unable to win meaningful platform concessions from a party that could well view him as an enemy invader, rather than a bluntly critical, but ultimately valuable friend.

Only time will tell how Sanders chooses to play out the end of his campaign.