That's a great question.
There is no great attachment on EITHER side of the ticket to the other. So could Joe concede and Kamala refuse?

Joe Hiden has been taking it on the nose from her... first in the debates when she called him a racist and then yesterday when she said "A Harris Administration with Biden" she tipped her hat as to who will wear the pants in THAT administration...

As a sign of his cognitive decline just think about this... would the guy who threatened to withhold funding IF the prosecutor pursuing Burisma (on whose Board Hunter sat or at least ghosted) were not immediately fired, put up with such condescending malarkey from his supposed running mate? Say what you will about him but somehow I don't think so. He used to be a whole lot sharper than he is now. Maybe Kamala is the trojan horse and Joe is merely the manchurian candidate...