That's my gut feeling.
I don't think it's at all impossible for Biden to win, but that's my gut feeling.
To be more specific: I think the "Red Mirage" scenario will happen. Trump will have a lead on election night and he and the Republicans will pull some fuckery to stop mail-ins from being counted in the right places.
If it gets to the Supreme Court, either Biden and the Dems will pull a Gore and surrender the election without a fight, or the Court will rule in his favor and hand him victory.
History will repeat itself.
It's a weird situation because he commands extreme loyalty from a very large group of armed goons that he doesn't actually directly control, cops. I'm not really sure if he can pull it off but at the same time I'm not sure anyone can stop him.