If America is the greatest nation on Earth, what's so wrong with saying so?Circumstance recently commanded the need for a taxi, my destination triggering in the driver the sort of incoherent recollections one normally expects from a great-grandfather who’s no longer allowed to touch the remote control. “I used to live down there, 1970,” he began, “Drove a 1968 Camaro, paid $1,495 for it … had a factory installed tape player.” Sorry, I didn’t ask whether it played eight track or cassette tapes. “Back then, gas was 27.9 cents a gallon, and smokes were 30 cents a pack. Now it’s...