• Warren accused Sanders' online supporters of "organized nastiness"
  • Candidates have a responsibility to reign in their supporter: Warren 
  • It looking increasingly unlikely that Warren will endorse Sanders

Sen. Elizabeth Warren, D-Mass., announced Thursday she’d be ending her run for the Democratic presidential nomination, opening the question of who she would be endorsing, if anyone. While Sen. Bernie Sanders, I-Vt., might have seemed like an obvious candidate to back, that seems highly unlikely after Warren blasted Sanders for failing to rein in his most zealous online supporters this week.

While appearing in an interview with Rachel Maddow on MSNBC Thursday night, Warren was questioned about her relationship with Sanders. Warren said that they had a friendship going back many years, but condemned the “online bullying” and “organized nastiness” carried out by some of Sanders’ supporters on social media.

Warren called out the targeting of “women of color, immigrant women” that “put them in fear for their families.” She acknowledged that Sanders and his campaign were not behind these behaviors, but also said candidates are “responsible for the people who claim to be our supporters.”

When Maddow asked whether this was especially an issue among Sanders' supporters, Warren replied that “it is.” Warren said she’d talked to Sanders about the issue but that the conversation was “short.”

While she stopped short of saying that Sanders did not believe the matter was his responsibility, Warren said the vicious online attacks between Democratic candidates’ supporters needed to be “reckoned with.”

On several occasions in the past, Sanders has called on his supporters to cease their aggressive social media attacks on his opponents.

For most of their campaigns, Warren and Sanders maintained a friendly peace, avoiding slinging mud at one another. That changed earlier this year, however, when Warren leveled claims that Sanders had once told her that a woman couldn’t win the presidency. This culminated in a heated exchange during a debate in January, where Sanders roundly denied Warren’s allegations. After the debate, Warren was seen refusing a handshake from Sanders after she accused him of calling her a liar.

More recently, Warren accused Sanders of being self-serving by supporting the nomination of a candidate with the most pledged delegates, even if they do not claim a majority.

Warren said she had spoken with Sanders recently, though she did not say what they had discussed. Although Warren’s attitude towards Sanders has softened, albeit modestly, her interview with Maddow can likely be taken as an indication that she won’t be offering to endorse Sanders any time soon.