The world is going through an angry and authoritarian spasm. Populists of Left and Right thrive by elevating grievances over potential solutions. Liberal doctrines – free trade, low taxes, private enterprise – are being squeezed by tribalism and identity politics.

There is an ugly element of Führerprinzip in the air, too. Followers of Jeremy Corbyn and Donald Trump have at least this much in common: that they will follow their leader through 180 degree rotations, clinging to some past position against what they imagine to be hostile media even after their principal has climbed down. As the popularity of interventionist policies grows, so does impatience with constitutional constraints and the demand for a strongman.