Elizabeth Warren is doubling down on Jacobin populism. Her proposed wealth tax on the US super-rich has just jumped from its earlier outlandish level of 3pc to naked confiscation of 6pc annually.

As she put it with forensic precision in her ‘calculator for billionaires’, Microsoft’s Bill Gates would have to pay an extra $6.38bn in the first year on his $107bn fortune. Amazon’s Jeff Bezos would have to pay $6.7bn. “Bottom line: If you made it big, you should chip in,” she says.

In a global economy of low returns a 6pc rate of wealth erosion would whittle down the great American fortunes of the early 21st Century to a small fraction over twenty to thirty years. The emerging US oligarchy - so feared by Thomas Jefferson - would all but disappear. That, of course, is the purpose.

The Democratic presidential candidate - the party's front-runner two weeks ago - also needs the money to fund her $20 trillion plan Medicare for All, supposedly without having to raise “one penny” of extra taxes on the middle class. This is a sort American NHS, without trolley-waits, de facto rationing, and Calvinism. It will even cover opticians and dentists.

The basic thinking is that if you can extract the accumulated wealth of the 75,000 richest US households, you can pay for the moon, though of course the dividend diminishes as the wealth vanishes - a problem for later.