Right now, the fault line is between whites and nonwhites. But as America grows more racially diverse, rifts will inevitably open between more groups. In a tribal system, every group finds itself at war with every other group. It’s the perfect perversion of the American ideal: “Out of many, one” becomes “Out of one, many.” This is the unhappy, blood-soaked story of countless civilizations around the world. It never ends well.

