You can measure the scale of an American president’s troubles by the number of skutniks he deploys during his State of the Union address. Every year during his big set-piece speech to Congress, the president will digress from the main thrust of his remarks to offer fulsome praise to some member of the audience in the gallery. This person will have been carefully selected in advance by the president’s speechwriters as an exemplar of some virtue and placed there for the purpose. The television producers will have been alerted in advance so that at the right moment, as the president...