The characteristic can-do vice is a sneaking envy of strongmen, but while their critics accuse them of suffering from Putin envy, what they really long for is a Churchill, though they’d take a de Gaulle in a pinch. Their characteristic virtue is having been fundamentally correct about the nature of our enemies in Nazi Germany, the Communist bloc, and the Islamic world, though in the case of Iraq their remedy exemplified another vice: an excess of optimism.

In the opposite corner are the more libertarian-leaning partisans of the mustn’t-do presidency, cautious and finicky about foreign entanglements and deeply suspicious of executive power at home. The mustn’t-do models are Cleveland, Coolidge, and Senator Robert Taft, which is not to say that they universally are admirers of the gold standard or are tempted toward mugwumpery, but that they desire to have a president who has a narrower conception of his role rather than a broader one. Of course they claim Reagan for their own. When it comes to the Founding Fathers, the mustn’t-dos like Jefferson and Paine. They see the Constitution’s separation of powers, the Tenth Amendment, and the congressional role in treaties and war declarations as limitations on government generally and on the president particularly. If they were British, they’d be Whigs.