Commentary I have committed to writing a book for the good people at Encounter Books (Roger Kimball & co.) on the you-could-almost-say-massive migration (some call it in-migration) to red states from blue that has been occurring the past few years—who’s making it, why they’re doing it, and what it means now and to the future of our country. The working title is “The Southbound Train,” which comes from the lyrics to Darius Rucker’s country hit “Wagon Wheel”: “Yeah, rock me mama like the wind and the rain/Rock me mama like a southbound train.” Actually, those words didn’t originate with Rucker but came from an unfinished song that Bob Dylan wrote nearly 50 years ago (1973). Nevertheless, Rucker’s version is the one most people know and for good reason—it’s great.  It should be no secret part of the reason I want to write this is that it’s also my story. At the end of May …