Populism? No thanks. I am not now, nor will I ever be, a populist. Evidently, that separates me from a growing number of commentators, including some conservatives, wistfully engaged in Washington's latest fad: over-interpreting Donald Trump's victory in the 2016 presidential election. The normally sensible Mike Lee, Republican senator from Utah, took to our pages to plead the case of "principled populism" -- which is akin to calling for a sober Bacchanalia. Not surprisingly, Senator Lee's brief doesn't get very far before strangling in its own illogic, as odes to populism inevitably do. The "characteristic weakness" of populism, he tells...