Actually 4 administrations, he left under Clinton over a disagreement about gays in the military (he was opposed).
Powell likes being the maverick moderate guy.
He has to go against the grain all the time, when GWB was president, he was the liberal, when it was Clinton, then Powell was the conservative.
Powell would find a way to argue with himself if need be.
He loves the limelight and the press, interestingly, the only President he never gave a hard time to, and pretty much followed, loyally, was Reagan.
Dick Cheney as SofD felt Powell was a royal pain, as did Clinton and his folks.
ALbright hated Powell with a passion after he used to snap at her.
Powell is a public relations guy, if Hillary Clinton was President, he would snap at her too, he just has to independent and gravitate away from whomever is in charge so that he call himself an independent.
Interesting analysis of the man. Perhaps that is what it comes down to.
An excellent analysis....you may be right.