You are incorrect about why Biden won. If it were not for progressives, Biden would not have won. Ilhan Omar and Rashida Tlaib won reelection comfortably and turned out the vote in their VERY important states for Biden.

NO House candidate who supported M4A lost reelection, and almost none who supported the green new deal. The Dem House members who lost were more conservative members who did NOT support progressive policies.

M4A has majority support IN THE COUNTRY. Not just Dems. Similar numbers for all of the major progressive policies (note this does NOT include defunding the police!).

The most progressive politician almost always wins, particularly if money and name recognition are somewhat equal. This is what happened in 2008, 2012, 2016 and again in 2020.

Bid/en barely won because Biden distanced himself from the progressives. Dems lost seats downballot for the same reason.

[edit] spelling error and I had the M4A support right, but not quite the green new deal in paragraph 2.