Imagine for a moment that you are Seth Wilbur Moulton. It is no great hardship. Scholars who follow these things rank you in the top decile of US congressional members for bipartisan conduct. You have the patriotic bona fides of a man who gave his best years to the Marine Corps. You have medals of valour that it took an investigative journalist to make public. Cosmic luck gave you an expensive education and the looks of a beau ideal American president from a moreish, if middlebrow, Netflix series. When you run for that office at age 40, all of Washington mumbles: “But of course.”

Then something novel happens. You fail. Three months into your candidacy, you are struggling to register in opinion polls or to qualify for televised debates with your fellow Democrats. Many people reading this will be wholly new to your name.

The parable of Mr Moulton signifies many things: life’s randomness, his own limitations, the still-early stages of a contest in which he may yet break through. But it also signifies the parochialism of the primary race. Mr Moulton’s “mistake” has been to run on foreign policy above all else. Democrats — electors and candidates alike — prefer to think and talk of other things. Where the outside world does impinge, it is as something to be saved from climate change, or from the Dickensian labour standards of too-free trade.