The thing is, progressive activists are right about public opinion on some of these issues. Most Americans do favor higher taxes on the rich, marijuana legalization and additional gun control. But too many progressives aren’t doing an honest analysis of the politics. They are instead committing what the journalist Matthew Yglesias has called “the pundit fallacy.” They are conflating their own opinions with smart political advice. They are choosing to believe what they want to believe.

They often do so by pointing to polls with favorably worded, intricate questions — and by ignoring evidence to the contrary. Affirmative action, for example, typically loses ballot initiatives. Polls show that most Americans favor some abortion restrictions and oppose the elimination of private health insurance.

By designing campaign strategies for the America they want, rather than the one that exists, progressives have done a favor to their political opponents. They have refused to make tactical retreats, which is why they keep losing.

I think Warren may have been the person most damaged by this dynamic in 2020. (And, yes, she was also hurt by sexism.) She could have positioned herself as the candidate who excited much of the left but was more acceptable to the center-left than Sanders. Instead, she mimicked Sanders, making many Democratic voters who were rooting for her worried that, like him, she couldn’t win a general election.

Or look back at the 2018 midterms. In competitive districts, candidates backed by progressive groups like Justice Democrats and Our Revolution were shut out. They lost in either the primaries or the general election. There isn’t a single Sanders-like member of Congress from a purple or red district. There are dozens of moderates.

Remember: The policy positions of Sanders, Warren and other progressives — on Medicare for all, for instance — are often closer to the views of most Democratic voters than the moderate position is. Yet many Democrats spurn the progressive candidate. These voters care more about winning than about perfect policy agreement, and they support the candidate whom they (correctly) see as more in tune with the full electorate.

The progressive wing of the party has still had a good few years, pushing the party left in multiple ways. Even Biden’s platform is strikingly liberal. But if progressives aren’t satisfied being influential runners-up, I would suggest three broad principles.