Let's just run Clooney as the Democratic candidate. It makes sense for a number of reasons. Though not a politician, he has far more on the ball than people like Reagan, Schwarzenegger or George W. People generally distrust professional politicians today (a factor that has probably helped Trump.) Moreover, Clooney is likely free of the compromises, sellouts, and obligations others have to make in order to attain office. Clooney knows how to work with various directors, agents, coaches, specialists and subordinates to get a major project accomplished. He himself has directed several major release film projects. His wife is a human rights lawyer. He’s traveled and worked internationally.
A challenge at this point for any other alternative Democratic candidate is gaining enough recognition and respect in the time remaining. Yet due to his career, Clooney is widely known, and everybody seems to like him – and I suspect he’d draw off a substantial portion of Trump voters (as well as from RFK Jr).
Finally, many people vote on superficial criteria — Clooney simply looks like a hero – especially next to the other two cadaverous options.