It's definitely not unprecedented. And JB Pritzker and Gavin Newsom are ready to step in if Joe gives it a go and decides to LBJ it and ride into the sunset on his old mustang instead of a horse drawn hearse. I think the physical demands of the presidency are greater than the mental challenges for a president of any age. I think it is a scary moment and Joe might realize he can allow his successor to be chosen in an open primary just like LBJ. It would be deja vu for RFK Jr's campaign and they would surge too. It would be much more fun than watching Brandon crumble and Trump implode in the highest stakes election since Truman v Dewey.