Former Vice President Joe Biden criticized Sen. Bernie Sanders on Sunday, arguing the senator has been inadequate in his response to harassment members of Nevada’s Culinary Workers Union say they’ve faced from some of Sanders’s online supporters after the group took aim at Sanders’s health care proposal.

In an interview with Meet the Press’s Chuck Todd that aired Sunday, Biden said the democratic socialist candidate “may not be responsible for it, but he has some accountability.”

“You know me well enough to know if any of my supporters did that, I’d disown them. Flat disown them,” Biden told Todd. “The stuff that was said online. The way they threatened these two women who are leaders in that culinary union. It is outrageous.”

On the night of New Hampshire’s Democratic primary, February 11, Nevada’s Culinary Union made its opposition to a key plank of Sanders’s platform clear by publishing fliers claiming Sanders is the only candidate who would take away the union’s health care plan. Sanders, of course, wants to enact his Medicare-for-all proposal — a plan that would abolish private health insurance and replace it with a government insurance plan.

It was a pointed political move: The Culinary Union, which represents some 60,000 casino and hospitality workers in the state, is one of the most powerful political forces in Nevada — and the flier was released less than two weeks before the state holds its caucuses.

Since the whole political world will now be watching whether @Culinary226 endorses someone in Nevada, which would be a genuine earthquake, here’s the candidate policy explainer they’ve sent to members: pic.twitter.com/X3Cgvr3YAX — Matt Pearce (@mattdpearce) February 12, 2020

The Culinary Union’s actions were sharply criticized online, and some of those critiques went far beyond typical online feuding and politicking.

According to the Nevada Independent, two top officials from the Culinary Union have “faced threatening phone calls, emails and tweets and say their personal information was shared online.” The report also said that much of the language directed at the union was bigoted and degrading:

Secretary-Treasurer Geoconda Arguello-Kline, for instance, has come under attack for her Nicaraguan heritage, and union spokeswoman Bethany Khan was accused of being paid off by former Secretary of State Hillary Clinton and other Democratic establishment types. In tweets, the union and its leadership have been referred to as “bitches,” “whore,” “fucking scab” and “evil, entitled assholes.”

It’s worth noting, however, that it’s difficult to verify just who was leveling these most malicious attacks, and that it is not always possible to identify the true political leanings of people who join harassment campaigns.

For example, the Nevada Independent found that one of those disparaging the union with bigoted language was a Trump supporter who opposes Medicare-for-all. And it also cannot be ruled out that some anonymous online attacks could be coming from covert social media campaigns designed to stoke political division.

Nevertheless, on Thursday, Sanders addressed the attacks on the Culinary Union.

“Harassment of all forms is unacceptable to me, and we urge supporters of all campaigns not to engage in bullying or ugly personal attacks,” Sanders said in a statement. “Our campaign is building a multi-generational, multi-racial movement of love, compassion, and justice. We can certainly disagree on issues, but we must do it in a respectful manner.”

But Biden said in his interview with Meet the Press that Sanders has not gone far enough and said that Sanders needs to “find out who the hell they are.”

“I’m hoping he’s looking. But I tell you what — so far I don’t think it’s sufficient just to say, ‘I disassociate myself,’” Biden said.

Sanders’s online army is an asset and a liability

Sanders has an extraordinarily large and enthusiastic set of supporters online, and their prominence in social media debates has helped drive home to the press and to Democrats just how beloved he is by his supporters. And Sanders’s big and hyperconnected online presence has helped him evolve into one of the most impressive fundraisers in American political history — in the fourth quarter of 2019, for instance, he raised $34.5 million, with an average donation of $18.53.

But some of his online supporters have also been criticized for being overly zealous, combative, or for bullying critics online, a criticism that began during his 2016 campaign against former Secretary of State Hillary Clinton, and one that has plagued his campaign throughout the 2020 contest — for good reason.

There have been a number of indicators throughout the primary so far that in online debate, a certain set of Sanders supporters — which is difficult to measure in size — is exceptionally abrasive and dehumanizing. For example, there are at least some Sanders supporters online who circulate memes likening former South Bend, Indiana, Mayor Pete Buttigieg to a rat, those who attacked an ALS activist over his support for Sen. Elizabeth Warren, and those who bombarded Warren with snake emojis following a disagreement between the two senators.

It’s within this context that the attacks were made against the Culinary Union officials. Again, it’s impossible to verify the identity of the sources of all these attacks — which Biden himself acknowledged in his interview. “I don’t know who these so-called supporters are,” Biden said. “We’re living in a strange world on the Internet. And sometimes people attack people in somebody else’s name.”

But it’s precisely because Sanders supporters online already have a reputation for inappropriate or belligerent behavior that this situation is more of a liability for Sanders. The whole episode is once again raising questions of how much a candidate is to be held responsible for the political culture that surrounds them online.