When Warren Harding was 19, in 1884, he bought a small Ohio newspaper, probably for $450. By the time he ran for president in 1920, it had made him rich. Harding campaigned as an entrepreneur, promising “less government in business and more business in government”. He is often described as the worst US president, until now.

The “businessman fallacy” — the notion that a rich businessman (never a woman) can run government better than a mere politician — is Donald Trump’s basic promise. That’s why the combustion of his son-in-law, fellow real-estate heir and senior adviser Jared Kushner — whose business dealings in the White House scream conflict of interest — is so telling. Kushner incarnates the businessman fallacy. Here’s why it is a fallacy.

? It is a lot simpler to run a company than a country. It’s not even the difference between checkers and chess. It’s the difference between checkers and playing simultaneous chess on infinite boards.