I speculated 2 years ago that Biden would not finish out his term. In a planned move, he will serve two years and a day and then resign, opening the door for a replacement. The thought at the time was positioning Kamala so she would still have the legal right to run for two terms on her own (10 years of D control). Kamala has been such a disaster that I don't know that they would put her in that position, knowing that she doesn't have the chops and could not win the next general election. However, IF they could convince her to resign with Biden, it opens the door for The Old Drunk Lady. If she would decline (would her ego allow it?) then the next in line is Patty Murray. this would give first woman, a reliable left control of the office, and someone the press would fawn over.

That's a LOT of ifs, but opens the aperture a bit to figure out the terrain as those people see it. Complex doesn't mean impossible.