The last “winning” (for them) play the Democrats ran was as follows:
Find a neophyte Senator with almost no national elective experience with a legal background who can (a) give a good stump speech, isn’t afraid to (b) throw red meat to the left, and (c ) is a person of color, and run them for president.
“No national experience” means there’s less of a track record for the right to attack. The stump speech and the red meat fires up the rubes. And the “person of color” matter increases urban voter turnout.
They’re going to run that play until it doesn’t work anymore.