 The Lord Almighty can convince him to quit the presidential race. If he changes his mind, however, or if those leading a mutiny against him succeed in sparking a floor fight after the Democratic National Convention opens on August 19th, Biden's running mate, Vice President Kamala Harris, is the best position to replace him as the party's nominee. She is the most natural choice for an endorsement, and Biden's feelings would still carry weight in the party.