Media outlets this week are all over a new Pew study that finds, the headlines promise, that President Trump's support is not quite as broad and not quite as happy as his stunningly stable approval rating might suggest. But what's striking from the numbers, at least as far as I can see, is not how much support Trump has lost but how, given the daily barrage of tweets and countertweets; ugly chants and ugly corruption trials (his campaign chairman); intense criticism in the media; all-out war in Congress; and foreign policy flubs and domestic failures, much remains firm, and how...