Although he hasn’t yet announced he’s running for the Democratic Party’s nomination for president, former Vice President Joe Biden is already being treated like a candidate, at least by the progressive wing of his party. He’s been making apologies for past policy decisions, like his support of the 1994 Crime Bill, and acknowledging his role as patriarchy incarnate during the Clarence Thomas-Anita Hill hearings.

Perhaps it was inevitable that a MeToo moment would soon follow. Over the weekend, Nevada politician Lucy Flores claimed that Biden had inappropriately invaded her personal space during a political event in 2014:  “I felt him get closer to me from behind. He leaned further in and inhaled my hair. I was mortified. I thought to myself, ‘I didn’t wash my hair today and the vice-president of the United States is smelling it. And also, what in the actual f–k? Why is the vice-president of the United States smelling my hair?’ He proceeded to plant a big slow kiss on the back of my head. My brain couldn’t process what was happening. I was embarrassed. I was shocked. I was confused.”

Flores didn’t say anything to Biden at the time, but in the years that followed, as she wrote in a piece in New York magazine’s The Cut, “my anger and my resentment grew. . . I may have been able to give Biden the benefit of the doubt. Had there not been multiple articles written over the years about the exact same thing — calling his creepy behavior an ‘open secret’—perhaps it would feel less offensive.”

Flores is an outspoken supporter of Bernie Sanders (she was on the board of a pro-Sanders group called Our Revolution), so her motivations for coming forward now could be viewed as both strategically political and personal (she recently launched a business dedicated to “empowering Latinas,” so her many media appearances about the incident are also on-brand).

But the kerfuffle also highlights an ongoing challenge for Democrats in the MeToo era: Where to draw the line between appropriate and inappropriate behavior by their male candidates? The party has thus far offered contradictory signals. Sen. Al Franken resigned over far less than what Biden is being accused of doing; but Virginia lieutenant governor Justin Fairfax, who has been accused by several women of sexual assault, remains in office. Bernie Sanders, Kirsten Gillibrand, and Kamala Harris have all been criticized for failing to handle sexual harassment allegations among their staff appropriately.

Biden moved quickly to deal with Flores’s charges. His statement on the matter was mealy-mouthed, suggesting the whole thing was just a misunderstanding. “Not once—never—did I believe I acted inappropriately,” he said. “If it is suggested I did so, I will listen respectfully. But it was never my intention.” He gave the obligatory nod to women’s “experiences,” as well: “We have arrived at an important time when women feel they can and should relate their experiences, and men should pay attention. And I will.”

But he also rallied his former female staffers, several of whom defended him vigorously against charges that he was a harasser. As well, Stephanie Carter, whom Biden infamously nuzzled on stage in 2015 after her husband, Ashton Carter, was sworn in as Secretary of Defense, wrote an essay defending Biden, noting, “The Joe Biden in my picture is a close friend helping someone get through a big day, for which I will always be grateful.”

This didn’t satisfy activists. Minnesota lawmaker and MeToo proponent Erin Maye Quade called Biden’s behavior “disqualifying.” “I look for people acknowledging and changing because of what they’re learning,” she told the Washington Post. “There’s nothing from him that acknowledges that ‘I’ve heard this, I’m listening, I understand.’”

Flores also seems unpersuaded by Biden’s attempt at an apology. She said, “I’m not suggesting that Biden broke any laws, but the transgressions that society deems minor (or doesn’t even see as transgressions) often feel considerable to the person on the receiving end. That imbalance of power and attention is the whole point — and the whole problem.”

It might end up being a problem for Biden if younger voters disregard his explanations of intent and focus instead on the feelings of the people (like Flores) on whom he practices his “affectionate, physical style,” as the Washington Post headline called it (prompting the question: Would the Post  have used the same headline had the politician in question been Mitch McConnell?)

A recent poll by Harvard Kennedy School’s Institute of Politics found Sanders ahead of Biden among 18-29 year olds—with Sanders at 30 percent and Biden at 20 percent among likely Democratic presidential primary voters. Yes, this is the same group that traditionally has the lowest voter turn-out rate in elections, but they are driving the conversation around MeToo, harassment, and consent. They could make Biden’s presidential primary run a hellscape of woke accusation, turning attention away from the reason he’s enjoying a commanding lead in most polls: voters’ confidence in his ability to take on Donald Trump.

Coincidentally, the same day Flores wrote about her experience with Biden, an essay by former New York Review of Books editor Ian Buruma appeared in the Financial Times. In it, he describes the fallout from his decision to publish an essay by a man accused of sexual harassment (a decision that ultimately cost Buruma his job). It carries some warnings for anyone on the left–even popular politicians like Biden—who think appeals to context and subtle distinctions are sufficient to calm progressive activists when MeToo allegations surface. Buruma writes, “This was not even a matter for debate. I was reminded by a member of the editorial staff that #MeToo was a movement, and by publishing the piece we were way out of line. We didn’t need nuance, I was told; nuance was considered to be a form of complicity.”