Let’s start with the fact that if you are a US voter in an American swing state, you must get out and vote for Biden, no matter what your personal feelings are, because Trump is a ravening maniac.
Now we have that out of the way…
"Progressives" aren't the issue in US elections, because they reliably show up each and every time to vote for whatever crappy old right-wing warhorse the DNC gives them.
For example, almost twice as many 2008 Hillary supporters jumped ship for the Republican as Bernie supporters did in 2016.
Progressives routinely show up for the Democrats at the second highest rate of any demographic, the first being of course senior citizens (who are always the top demographic for both parties).
Progressives do this knowing that all their political beliefs, beliefs which would be considered mainstream in any other developed country, will be routinely mocked all the way through the election.
And they do this knowing from bitter experience that all the Democrats' electoral mistakes will be blamed on them. Progressives do this because it’s the right thing to do, and yet year after year they get shit on by right-wing Democrats.
In fact, the people who voted for Obama and not for Hillary were not progressives. They were poor people! They were people of color, they were people who slip a little further off the net each and every day.
After eight years of Obama, the poorest 50% of America was in an even more dire state than when they started. Then they were told that "America was already great" - that this was as good as it was ever going to get for them, that no help was ever coming.
No wonder they stayed at home.