In reality, the nomination of the pro-war corporate shill Biden and the right-wing character of his campaign constitute a devastating refutation of the central claim of Sanders and the various pseudo-left organizations that support him: That the Democratic Party can be pushed to the left and transformed into an instrument of progressive change through pressure from below.
Sanders’ acknowledgment of Biden’s refusal to support even his mild reform proposals did not prevent him from affirming his full backing for the Democratic campaign. Since pulling out of the race for the Democratic nomination last April and endorsing Biden soon after—reprising his endorsement of Hillary Clinton in 2016—Sanders has demanded that his supporters line up behind Biden and attacked those who criticize the Democratic ticket.
-- Jacob Crosse and Barry Grey, "Bernie Sanders offers left gloss to Biden’s right-wing campaign" (WSWS).