I don’t think Obama is evil, by the way. The reason why he was such a bad president is that he is extremely vain. Three autobiographies one after another are a good indicator of that.
He needs to shine but he was elected with zero experience and knowledge of how to do anything. Unlike Trump, who has the rare yet extremely useful defect of not being able to conceive of anybody outshining him, Obama couldn’t appoint anybody but complete mediocrities to his cabinet. Anybody half capable would have made him feel deficient, so he had to surround himself with doddering fools like Biden, Arne Duncan, John Kerry, Yellen, Holder, and all the rest of those sad asses.
Obama isn’t stupid, though. He knows he messed up. Maybe he isn’t letting this knowledge to reach him consciously but he knows. The most recent autobiography points to the need to self-justify. He’ll now try to replay his presidency through Biden to prove to himself that he wasn’t completely useless. Which he was, as we all know.