Still, among these Mr Trump stands out as potentially the most dangerous. That’s not just because he hardly has integrity on the scale of Eisenhower or humility that comes close to Truman’s. Rather, it’s because he is the boss during a period when the declining performance of the US economy means the legitimacy of liberal democracy is being tested perhaps as never before.
Whatever the fears of Reds under the beds that periodically obsessed 1950s America, Truman and Eisenhower learnt that they could rely on the US economy to make voters feel good. Mr Trump can’t do that. Besides, he has contempt for the liberal order and, like many non-economists, is an instinctive mercantilist, imagining global trade to be a zero-sum game where there are only winners and losers.