Obama was counting on Hillary to protect his secrets, his criminality. Now that Hillary’s campaign is collapsing, Biden is his only hope.
I suggest a quick sex change for Biden to have any chance to win, as having Caitlyn as a running mate wont be enough to put them over the top.
Warren will be his running mate conditioned upon Biden promising to only serve one term so that Fauxcahantas has her turn in 2020.