This is no new problem with strongmen. In the 19th century, Karl Marx faulted critics of Napoleon III — the nephew of the first Napoleon who managed to get himself crowned emperor of France in 1852 — for losing sight of the structures that enabled him to ascend to power. In such readings, he appeared as “a bolt from the blue” with “a personal power of initiative unparalleled in world history,” even as opponents depicted him as a grotesque upstart. Studies of Mr. Trump similarly pull in two directions: Both a buffoon and a mastermind, he appears as a figure who somehow blundered to the top of the American state.