I heard this posited on the radio the other day: Joe Biden selects Michelle Obama as his running mate. Assuming he / she wins the general, Biden assumes the presidency. Sometime within the first half of his term, Biden resigns for 'health' reasons, which, because of his current apparent mentally enfeebled condition is entirely plausible. Gobs of money will be parked away for him to get out. A dream of his to have been President of the U.S. is thereby satisfied and the Obamas return to 1600 Penn. Av. without having to endure the rigors of campaigning and primaries.