When Barack Obama launched his White House bid 12 years ago, he already had a library of well-crafted policies. Some were bold. Others were small-bore. Behind each position was a bench of experts. The same went for John McCain, Hillary Clinton, John Edwards, Mitt Romney and other 2008 contenders. Now we could be living in a different century. With the exception of Elizabeth Warren, whose campaign has yet to catch fire, today’s Democratic aspirants are content with a brassy slogan. Policy wonks might as well join the Mississippi gopher frog on the endangered species list.

The shift has little to do with ideology. Moderate Democrats, such as Beto O’Rourke, are as allergic to detail as are their rivals on the left. What marks the field out is comfort with post-literate politics. Who can blame them? Donald Trump has altered what it means to run for high office. No White House contender ever came near his blend of fantasy and falsehood. He won all the same. He may well do so again. The least bad thing you could say about Mr Trump’s fabulism is that he paid no price for it. But the truth is uglier: it may well have brought him victory.

Little wonder the habit is spreading. It was only a few months ago that Mr Trump dropped his magical claim that Mexico would pay for the border wall. There is little sign that voters who believed Mr Trump in 2016 hold him to account for failing to shake down America’s southern neighbour. Quite the reverse. They blame Democrats for keeping the US taxpayer off the hook. Good intentions are a weak differentiator. The left may prefer white magic to Mr Trump’s black. But everyone is dabbling.