Brexit – Britain's vote to exit the European Union – is invariably mentioned in the same breath as Americans deciding to put Donald Trump into the White House.

A rush of populist blood to the head. A breakout of the political id. A xenophobic, even semi-racist inward turn by voters. A self-inflicted national blunder – for Britain, the worst since losing the American colonies. A Rolls-Royce driven by drunks. The long-lost final episode of Fawlty Towers, as one commentator smirked.