Hillary Clinton was frequently on the offensive at her first face-off with Donald Trump, but she had no response to one particular attack: “What did we learn with DNC?” he asked. “We learned that Bernie Sanders was taken advantage of by your people.”

Unlike most Trump claims, this one had the advantage of being true. And it rubbed salt in a wound that could well cost Clinton the presidency.

In late August, Neera Tanden, the president of the Center for American Progress, longtime Hillary confidant and potential future White House official, offered a candid public assessment of recent political history that cut against conventional wisdom. The 2016 Democratic primary contest, she asserted, was “much tougher” than the 2008 version.

All throughout the long, arduous slog between Clinton and Bernie Sanders, liberal pundits downplayed the significance of internal party discord, invariably insisting that it paled in comparison to the brutal Clinton-Obama battle eight years ago. They routinely assured nervous partisans that Democratic voters would quickly cast aside their internecine grievances and unite for the general election, allowing Clinton to waltz smoothly into the Oval Office.

But it turns out that Tanden’s evaluation was on the money. And her impulsion to profess it publicly, in a podcast interview, suggests that enduring fissures on the left are of paramount worry to Team Clinton — as they well should be. Trump certainly senses an opening: after hacked audio from a closed-door, high-dollar fundraiser showed Hillary dismissing the Sanders candidacy as a “false promise” latched onto by naive youngsters toiling away “in their parents’ basement,” Trump pounced, tweeting: “Crooked H is nasty to Sanders supporters behind closed doors. Owned by Wall St and Politicians, HRC is not with you.”

Despite a dogged PR campaign by Clinton loyalists, legions of Sanders devotees have refused to embrace her. Many remain chastened by a primary process they see as having been “rigged.” Others are disturbed by Clinton’s recent overt appeals to Republican national security hawks and billionaire financiers. Whatever the reasons, a YouGov poll released September 15 showed that only 51% of Sanders supporters plan to vote Hillary—a six percentage point drop from one month prior. (Conversely, 15% of Sanders supporters stated that they plan to vote Trump, a 10% increase over the same period.) Other polls indicate Clinton’s “favorability” rating has sunk to all-time lows, driven in large part by hostility from self-described liberals and Democrats—especially young ones. Fully 77% of voters aged 18-34 say they view Hillary as “dishonest.” Even Trump scores better on that metric.

There’s something elemental going on here. The Sanders campaign amplified long-simmering dissension in the Democratic Party coalition, and the fracture, now exposed and widened, can’t be easily fixed or papered over. This is ironic for any number of reasons, one being that the media has spent well over a year fixated on the internal turmoil wracking Republicans—yet it turns out the divisions between Democrats may be far more deep-seated and electorally consequential.

In that same interview, Tanden went on to blame Sanders himself for the party’s rift, decrying his allegedly vicious “character attack” as having done “significant damage to [Hillary’s] negatives.” This is somewhat counter-intuitive, given Sanders’ famous declaration last October that the American people were “sick and tired of hearing about [her] damn emails,” effectively taking off the table what was then an active federal criminal investigation targeting his opponent’s conduct.

Nevertheless, Sanders drawing attention to her fondness for Wall Street and military interventionism almost certainly did have a lasting impact on progressive-minded voters, particularly those under 30 who might not have been previously aware of the Clintons’ long, blemished record.

So it stands to reason that of the troubles presently besetting Hillary, foremost is the resolute antipathy toward her within the leftward elements of the Democratic Party’s reshaped and unwieldy coalition — especially among people whose political consciousnesses were enlivened by Sanders. This newly emboldened cohort have coalesced around a wholesale critique of the current political order, and far from giving her a pass, they situate Hillary firmly at the center of said critique. The result is not a situation that can be resolved by Sanders showing up beside her at a few “unity” rallies, or some piffling additions to the toothless party platform; rather, the divides made plain by his candidacy portend a realignment in the composition of the electorate writ large.

Eight years ago, the contrasts highlighted by the Obama-Clinton soap opera were ultimately less than advertised. Obama brought Clinton into his administration, setting her on course to successfully seek the nomination shortly thereafter. Despite outsized media attention on a handful of so-called “PUMAs,” Obama consolidated Democratic voters by more than enough to convincingly win the general election. By contrast, the 2016 conflict was at its heart ideological: the main source of tension wasn’t a personality clash or sore feelings among staffers, but a core difference in vision about the very nature of the political system.

This may help explain why despite feverishly promoting superficial notions of “unity,” the Clinton operation has done minimal outreach to the organizers who actually helped facilitate Sanders’ breakthrough electoral performance. One former senior Sanders staffer who requested anonymity recounted applying to the Clinton campaign for a position at the urging of Democratic operatives, only to be unceremoniously rebuffed at both the state and national level. “I chatted with some people at the convention, but it was one of those things where you sense that it was not going to go anywhere,” the person said.

Sean Kay, a professor at Ohio Wesleyan University who coordinated foreign policy advisory efforts for the Sanders campaign on a volunteer basis, said that neither he nor his colleagues have been approached by anyone associated with the Clinton operation. Kay, who is now a Hillary supporter, sees this as a potentially dire tactical mistake, and notes that the Clintons’ line on foreign policy since the convention might have permanently disenchanted otherwise-gettable progressives. “When those voters that rallied around Bernie Sanders start hearing stories about how they want to reach out to Henry Kissinger and how Paul Wolfowitz has reached out to Hillary Clinton, that doesn’t help. I think it weighs down the campaign,” he said. “I don’t think it was helpful to the Clinton campaign that the first steps out on this were how to reach out to the neocon GOP foreign policy establishment, as opposed to first really having a conversation with the core base of the Democratic party — then broadening out from there.”

It may now be too late for any such “broadening.” Part of the reason for this is fundamental, and can’t be addressed by orchestrated entreaties to disobedient “millennials.” There should be little doubt that among a certain left-wing contingent — call them the newly-enfranchised, highly-ideological activist heart of the party — a level of animosity exists toward Hillary that never existed toward Obama in 2008 or even 2012.

The reasons are manifold. The anti-establishmentarian left has undergone a degree of radicalization in the eight years since Obama assumed office, driven by events ranging from the Occupy movement (the messaging of which clearly presaged Sanders’ candidacy) to Black Lives Matter, the Edward Snowden surveillance revelations, and increasing alarm about fracking and climate change — much of it magnified by social justice-inflected Twitter culture. Among the youth, there’s a tinge of philosophical dissidence in their political outlook that existed only inchoately in 2008, if at all. (Sanders did call for a “political revolution,” not minor tinkering around the edges.)

During the Obama-Clinton saga, the overriding priority for this group was to remove Republicans from office after eight long, dreadful years of George W. Bush. Obama, buoyed by a surge in youth support, was seen (rightly or wrongly) as a break from Democratic Party orthodoxies — namely staid Clintonism.

But the progressive left now has different imperatives. It’s not enough to warn about the dangers of evil Republicans gaining power. For them, distressing maladies have persisted and in some cases worsened under an outwardly liberal Democratic president, so something new is needed. Whatever else Hillary might be, “new” she is not.

Their resistance to falling in line may also have to do with the younger generation’s reliance on social media, which fosters a kind of ingrained skepticism. Whereas passively consuming cable news (an increasingly geriatric activity) encourages adoption of whatever the chorus of anti-Trump pundits are fulminating about on a given day, younger people curate information much more assiduously than their elders — filtering out the superfluous hysterics and nonsense. Indeed, an entire new media ecosystem developed around the Sanders campaign, feeding followers constant updates for months upon months about the perceived corruption of Hillary. So it’s not surprising that people who’ve been immersed in this world might resist demands to suck it up and capitulate to party hacks whom they view not as uneasy allies, but enemies.

For many of this Sanders cohort, the experience of attending the Democratic convention in July was profoundly souring. “What bothered me most about it was that these were people who spent over a year registering voters for the party, and we were so disrespected,” Tascha van Auken, a Sanders delegate from New York, told me. She founded a volunteer group called Team Bernie NY in the summer of 2015, working tirelessly to sign up new Democrats in advance of the state’s closed primary the following April. Van Auken described a series of slights, affronts, coordinated stifling attempts, and even outright attacks on Sanders delegates at the convention, which in aggregate caused her to wonder whether the Democratic Party itself was fundamentally broken, and ever worth attempting to work within. The feeling hasn’t gone away.

“I think what was ultimately surprising to me about my experience was not the ridiculous spectacle or even the excessive patriotism,” she said of the convention. “But that Democrats clearly had no interest in welcoming this new progressive component into their party.”

Van Auken and others identified as a prime culprit for their continuing disaffection the convention “whips” deployed to quell protest activity among the various delegations. Numerous members of the New York Sanders contingent characterized the behavior of these whips — who sported bright yellow visibility jackets — as ranging from moderately officious to aggressively hostile. One particular whip would snap ostentatious smartphone photos of Sanders supporters who were insufficiently compliant.

“Hillary whips were checking our credentials over and over again and accusing us of not being delegates — they made some delegates cry,” recounted Emmanuel Ackaouy, another New York delegate, who previously regarded himself as a stalwart Democrat but has since felt compelled to reevaluate. “It was really confrontational and uncomfortable,” he said. “It felt borderline fascist.”

These are the very types of grassroots progressive activists who might have trekked to swing states and organized for the Democratic nominee; instead, they are largely sitting the presidential contest out, focusing on local races, if they remain involved at all.

Then there’s another aspect to all this, which many are reluctant to acknowledge. Some of the left-wing Sanders faithful — granted, likely a minority, but a recognizable minority nevertheless —believe a Trump presidency would ultimately wreak less destruction than a Clinton one. Alexis Edelstein, a former Sanders delegate from Playa del Rey, California who was active in facilitating much of the organized dissent at the convention — including a “occupation” of the media tent on July 28 — takes this position.

“I’m hoping that Hillary doesn’t win,” Edelstein, an immigrant from Argentina, told me. “Trump’s an asshole but I feel like he’s full of hot air. HRC’s calculating, she’s conniving. Trump I think is just — he’s got a huge head. He probably bit off more than he can chew.”

The left-wing case for Trump isn’t necessarily a cogent or well-reasoned one, but it shouldn’t be surprising that some would gravitate to it given the weakness of the current left-wing case for Clinton, who’s made it abundantly clear that she is far more comfortable crafting a message aimed at wayward Republicans and moderate conservatives than one aimed at populist-oriented progressives.

Another Sanders delegate from California, Michael Fortes, recalled a jarring moment at the convention that bears on this dynamic. At the moment Hillary was formally nominated, he said, a number of delegates could be heard exclaiming, “Hello President Trump!” It was more an expression of defeatism than any celebration of Trump. But the sentiment that we’d be better off if Clinton loses does exist, and there’s no sense ignoring it.

“To a certain degree, Trump’s overtures to the left are working,” Fortes said.

Edelstein added that he and fellow Sanders delegates attempted to convince their compatriots of this view, encountering some resistance and some receptivity. Their ultimate hope in wishing for a Clinton defeat is that it will embolden the organized left-wing to seize power in 2020.

“If Hillary wins in November, I feel she will do whatever she can to squash the progressive movement,” he said. “That movement dies.”