There is a remedy for the madness of King Donald — are we too cowardly to use it?

When Louise and I lived in Germany in the 1980s, we visited Neuschwanstein Castle, the fantasy palace perched on a Bavarian cliff that looks like it escaped from a fairy tale. Tour guides will tell you about its beauty and its role as an inspiration for Disney, but they’ll also share a more unsettling story that today echoes Donald Trump.

Neuschwanstein was built by King Ludwig II, a ruler who withdrew from reality, governed through spectacle instead of policy, ignored his ministers, and...