You're right. Progressives do not have the votes - to outvote the centrists. But centrists do not have the votes either. Do you think Biden's poor poll numbers are because of Republicants? Uh uh, Repubs would disapprove almost across the board by definition. The poor polling is because of disapproval of Democrats.

Centrists/corporatists - I like the term Conservadems - have been in lock-step control of the Democratic party for too long now and have cocked everything up. They need to get out of the way and let progressives have their chance. There aren't many chances left, if any at all.