Most socialists are cleareyed about Mr. Trump as a threat to most Americans, sowing divisions among working people and marrying populist rhetoric to policies that only further enrich his powerful friends. Nor is it uncommon to hear young leftists denounce the Republican Party as the greatest threat to progress in the United States.

I share the belief that having Joe Biden in the White House would be far less damaging to most workers than another four years of Donald Trump. Mr. Biden is at odds with the progressive, labor-oriented wing of his party, but every poor and working person in America, along with every socialist, would be better off butting heads with a White House filled with centrist Democrats than one filled with Trump appointees.

But that doesn’t mean socialists must fall in line behind Mr. Biden. There is an anti-establishment mood growing in this country, and not only among socialists; millions of voters are distrustful of mainstream politicians and sick of choosing between two parties captured by the corporate elite. Bernie Sanders represented a real alternative to many of them, and Joe Biden does not. And they are frustrated by the lack of recognition: In both 2016 and 2020, the runner-up in the Democratic primary has been a democratic socialist, but you wouldn’t guess that by the lack of concessions to his base.