Hearken, youngsters, to another tale of those ancient days, the Eighties, when nobody wore bicycle helmets and there were precious few outbreaks of easily preventable infectious diseases owing largely to the fact that your mom didn’t get her health-care advice from the same place your dad got his porn. Dangerous days, they were, full of scraped knees and hurt feelings. The name “Tipper Gore” was never spoken casually; it was spat in contempt if it had to be uttered at all. The now-former Mrs. Al Gore was the leader of an organization called the Parents’ Music Resource Center, a coven...