Some random thoughts...
ol' white joe IS going to be primaried.
RFKjr.'s candidacy guarantees that.
Assuming joe stays in, there could be a contest for the VP slot. There's nothing that says the president can't run with a new VP -- look at Roosevelt in 1944 (those close to him knew he wasn't long for the world, and that his existing VP, the communist Henry Wallace, could not be allowed to become president -- hence, Harry Truman replaced him). I sense that most folks -- even the most ardent dem-coms -- realize that ol' white joe probably would not finish a second term. So they'd better get a competent replacement lined up.
But what if ol' joe suddenly drops his candidacy at some point, probably in early-mid 2024? That will throw the dem-communist race into a tizzy.
In that case, what does kamala sutra do?
She'll have to run all over again, and it will probably be pretty much for her like it was in 2020 -- she's a loser from the get-go.
Next, Newsom will make his play. But Greasy Gavin™, despite being a smooth talker, is going to wilt face-to-face against Bobby Jr.
michelle obama? A wild card. But I don't think this woman really has any drive to be president. She wouldn't want to be bothered.
So... who does that leave at the top of the dem-com heap...?