Exactly four years ago I wrote a column suggesting, tongue firmly in cheek, that Donald Trump was about to win the US election. In retrospect, it wasn’t particularly good satire. It was safe, and somewhat on the nose, because Trump obviously wasn’t going to win.

There was simply no way a carnival barker who had never spent an hour in public service and whose tacky, unapologetic hedonism flew directly in the face of conservative values, could ever become president of a vast, complex and deeply religious democracy such as the US...