Why do billionaires think they can be great presidents?

Former New York Mayor Michael Bloomberg is expected to file papers today to be on the Democratic presidential primary ballot in Alabama.

The other billionaire in the race is Tom Steyer, the California hedge fund manager and liberal activist. He’s in hot water after the AP reported a top aide was offering campaign contributions to Iowa politicians in exchange for endorsements.

Another billionaire wading into presidential politics: Bill Gates. He recently criticized Elizabeth Warren’s wealth tax.