The Biden campaign knows protesters.

Having appeared as uninvited guests at speech after speech, rally after rally, officials have dealt with anti-Biden evangelists on a semi-regular basis for much of his year-long campaign. They’ve perfected the art of physically protecting their boss, who typically stands still, waiting for the yelling and chanting to stop. One time, he quipped, “this is not a Trump rally,” before letting them press on.

Sunday night’s televised debate was held without an audience. Which is why it raised eyebrows when, in a briefing with reporters, Anita Dunn, a senior adviser and strategist for Biden’s campaign, likened her boss’ only political opponent to a disruptive dissenter just minutes after he sought to make an explicit unity pitch to the country during a state of national emergency.

“I think it’s fair to say that Vice President Biden showed up to a debate tonight and for two hours graciously dealt with the kind of protester who often shows up at campaign events,” she said, with a pause, during a briefing call with reporters following Sunday night’s debate. “On live television.”

She was, of course, referring to Bernie Sanders.

The comment—which was stated on the record and was the first of several post-debate remarks by four senior campaign officials—seemed a stark contrast to the approach Biden had made before and during the debate, seeking to extend a hand to his opponent’s supporters should he defeat Sanders soundly on Tuesday.

Before the briefing call, Biden took two steps towards appealing to more liberal voters, using versions of ideas put forth by Sanders and Sen. Elizabeth Warren (D-MA) as inspiration. First came an endorsement of Warren’s bankruptcy plan, pleading to repeal parts of a 2005 law they had famously sparred over 15 years ago while Biden was in the Senate. (Biden claimed on Sunday night he did not help write the bill, despite a mountain of evidence that indicates he worked closely on it).

Then he pivoted towards Sanders. Using portions of a 2017 Senate bill the Vermont Independent introduced to make public colleges and universities tuition free for families earning less than $125,000, Biden specifically credited Sanders for his new stance. But the bill is different from what the senator has campaigned on during his second presidential bid—which would make all of those institutions universally tuition-free and not dependent on income. On stage, Sanders said Biden was behind the curve for adopting a position that was part of the Democratic Party’s platform under Hillary Clinton four years ago.

While it’s unclear if Dunn was speaking in an offhand fashion, Biden’s communications team seemed to endorse her remarks, with his national press secretary posting three flame emojis on Twitter, indicating it was a positively fiery proclamation from #AnitaDunn, as she was labeled in the tweet.

“I think he’s doing phenomenal on that front,” Barry Goodman, a top Biden bundler and Democratic National Committee member, said when asked about squaring Biden’s unity with Dunn’s comments. “Someone may be a liberal, someone may be a progressive, someone may be a moderate. We can’t win doing that,” he said. “I think they’ll all come out for Joe.”

During the debate, which was held in Washington, D.C., instead of Phoenix, Arizona, to help minimize the spread of COVID-19, Biden and Sanders engaged in a back-and-forth over votes of decades past, but generally remained civil in tone. But the virtual spin room suggested there’s some fine-tuning to be done on the part of party unity.

Goodman’s thinking — which echoes others in Biden’s orbit — is that self-proclaimed Sanders supporters will come over to the former vice president once he is the presumptive nominee, or even before that, seeing what's at stake against President Donald Trump.

A rogue comment from a campaign official or surrogate, which appears to buck the candidate’s own calls to come together just hours prior, wouldn’t likely change anything. “These guys are all smart,” Goodman added, when pressed again about Dunn’s comment specifically. “They’re all brilliant people.”

Steve Schale, the head of the pro-Biden super PAC, Unite The Country, acknowledged that some are guilty of “throwing sharp elbows” because there’s still an active primary going on.

“I don’t care how hard the candidates try themselves to show a good face, the nature of operatives is to run as hard into the wall as you can until there’s no longer a campaign,” he said. “That doesn’t mean there’s no work that needs to be done.”

Khizr Khan, the Gold Star father who strongly rebuked Trump at the 2016 Democratic National Convention, said that “surrogates and others can express their thoughts the way they wish to, those are their words,” acknowledging that it’s not always the most helpful. Khan, who endorsed Biden in November and was speaking in a personal capacity, said that Biden’s pledge to support and campaign for Sanders if he were to become the nominee “speaks volumes of the person’s nature and intentions to unite all of us.”

Reached for comment by The Daily Beast, a Biden adviser said they “came into this debate seeking to build a bridge,” adding that they “extended a hand but the campaign felt that Senator Sanders responded by unloading old oppo and grievances that had already failed to be productive in previous competitions.”

The adviser went on: “We needed to defend ourselves, and we did. But make no mistake: Our hand is and continues to be outstretched. Vice President Biden and Bernie Sanders are friends who share in the most important of values and causes, and who are both deeply committed to their legacies including unifying this party and defeating of Donald Trump.”

But while some Democrats brushed off Dunn’s comments as “tough post-debate spin,” as one moderate strategist put it, others in Sanders’ world heard alarm bells going off.

“In light of this, I think we should stay in til the convention,” Heather Gautney, a senior policy adviser for Sanders, tweeted in reference to her remarks. The Sunrise Movement, a group of young activists who pushed for the idea of a Green New Deal, strongly condemned the comments.

“The Democratic Party faces a stark generational divide between younger and older Democrats. Condescending to these already alienated and frustrated younger voters, as @JoeBiden advisor Anita Dunn did, could cost us the general election -- or fracture the party forever,” the group wrote on Monday afternoon.

To be sure, Sanders has not exactly sent the welcome wagon to Biden’s fanclub. Just after Biden won the South Carolina primary by a landslide, due largely to a strong showing from African-American voters who effectively helped launch a string of successes on Super Tuesday and beyond, Sanders said that the “political establishment” was working hard to coalesse around Biden, a remark that offended several Biden loyalists, including hOUSE Majority Whip James Clyburn, who told The Daily Beast: “I find it very interesting that someone is referring to African-American voters in South Carolina as the establishment.”

When asked what specific actions the Biden campaign can take to appeal to Sanders’ supporters, one senior Sanders campaign adviser directly involved in strategy listed off a series of action items.

“They need to not make the mistakes of 2016, and say to the Sanders movement that you guys have nowhere else to go so shut up and take it,” the official said. “That’s not going to work.” On top of that, Biden would need to show “a real deep respect” for Sanders “and the way he changed this game.” Finally, the source contended: Biden’s team better not start “thinking that a false unity is enough.”

“You can’t just say let’s unite and beat Trump,” the senior official said. “They have to acknowledge that they understand what this movement is.”