I think Biden/Harris will run as the incumbents.
For sh*ts & giggles, I think Trump will be the Republican nominee, but I don't know who his running mate will be.
I could see Cornel West pulling a very small number of votes from Biden/Harris, giving Trump a tiny edge. However, I think that Trump's running mate will have a significant impact on his candicady.
A moderate running mate like Chris Christie would be a good choice for Trump; somebody as far right as DeSantis could alienate a segment of voters.
Ultimately, I think that Biden wins re-election, but I can see Trump pulling off the upset if he has a strong running mate.