Sanders has directly appealed to his young supporters to put aside their differences and support Biden.
The Progressive Turnout Project, Indivisible and the Human Rights Campaign all endorsed Biden this week.
But some on the left are still not sold.
Nomiki Konst, a self-identified democratic socialist and activist who has worked for Our Revolution and The Young Turks, said the unease about Biden is a common sentiment in her circles.
Konst said Biden’s campaign has been “invisible” since he became the presumptive nominee. She and others are upset with Biden for putting Democrats distrusted by the left in key positions within the campaign.
Former Treasury Secretary Lawrence Summers is acting as an outside economic adviser. And former Sen. Chris Dodd (D-Conn.), is helping to lead the search for a woman to be Biden’s vice president. Dodd is a longtime lobbyist who was featured in a 1990 GQ article that described an incident in which he allegedly sexually harassed a waitress during a dinner with the late Sen. Edward Kennedy (D-Mass.) in the 1980s.
“I am disgusted about Chris Dodd,” Konst said. “I mean how out of touch are you? … I think we can make some real demands. Women’s groups should not be sitting silent.”
The appointment of Dodd comes as Biden has faced a sexual assault allegation from former Senate staffer Tara Reade, which has further troubled the left. There have been op-eds by some Biden critics calling on Democrats to replace him, and on Thursday, Reade called for Biden to end his campaign.
Biden denies the allegation and top Democrats have rallied to his defense.