Bernie Sanders and His Internet Army

When the story broke this month detailing the private conversation between Mr. Sanders and Ms. Warren about female electability, Sanders surrogates received a message from the campaign, advising them against going out of their way to engage with it publicly.

But later that day, Mr. Sanders’s campaign manager, Faiz Shakir, told CNN that whoever had pushed the Warren story was lying. Shaun King, a civil rights activist and prominent Sanders supporter with more than one million Twitter followers, said he saw an opportunity.

Among other widely circulated tweets, Mr. King wrote that he had spoken to Warren campaign staff members who reported that she “routinely embellishes stories.” He alleged that the Warren campaign and its allies “leaked this attack against Bernie to the press for political gain.”

Eventually, Ms. Turner, the campaign co-chair, got in touch. “She called me and said, ‘Shaun, just let up on it,’” he said. He did, to an extent. But by then, much of the Sanders-aligned internet was about to begin tweeting snakes at Ms. Warren and her supporters en masse.

In that instance and more than a handful of others over the past year, the campaign has publicly distanced itself from the rancor. Mr. Sanders’s wife, Jane, called for unity as the Warren squabble persisted. Mr. Sanders weighed in when some followers scorched Mr. Barkan, the activist with A.L.S., after his endorsement of Ms. Warren. “Bernie and all of his staff and surrogates were incredibly gracious and kind when I made the difficult decision to endorse one of my heroes over the other,” Mr. Barkan said in a statement.

The campaign recognizes the possible political downsides in any extreme behavior, but aides are perhaps most wary of the “bro” portion of the “Bernie Bro” descriptor, as Mr. Sanders prepares to make his case to a diverse Democratic electorate later in the primary calendar. Ms. Ford, the Sanders spokeswoman, said opponents were perpetuating “a false myth to discount the diversity of our supporters.”