...would you be comfortable with your kid acting like they act...or speaking with them at length. Would you, yourself, want to speak with them or attend a lecture given by them.
Trump fails that. Biden fails that. I'd be interested in hearing both Bushes, Obama, Clinton, Reagan in his prime. Carter seems like a bore. No Nixon. No Kennedy. No Johnson. Yes Eisenhower and Truman.
It's like obscenity and pornography...you know it when you see it.
That could be pretty rare or the norm, depending on the criteria. Like if it's personality and some kind of professionalism to act the part, then Trump fails and perhaps most passed.
If it's people to admire as a talented leader, then Biden surely fails.
“the intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not.” - Peter Medawar11