Joe probably has no idea. He has few coherent ideas at this point.
But my guess is that the Clinton mafia is trying to shake his team of the notion that they can pass the nomination on to Michelle instead of Hillary. They have slowly been increasing the stakes from an adult woman’s claim now to an early-teen girl’s claim. They could of course go far worse if his team doesn’t shape up.
Just a guess.
A dementia patient loses the most recent memories first. Stuff from long ago hangs around the longest.