It represents a large portion, but progressive policies are widely popular. Even in states Trump won there were votes passed to protect abortion access and increase minimum wage.

Most people vote based on vibes, and there were no progressive or positive vibes put forward by the dems this campaign. They signaled a ‘lethal military’, tighter borders, and sought endorsements from prominent Republicans, trying to win votes that would never go to their party anyway, alienating anyone who might have believed in the genuineness of the dems as ‘progressives’.