America is coming apart. For most of our nation's history, whatever the inequality in wealth between the richest and poorest citizens, we maintained a cultural equality known nowhere else in the world—for whites, anyway. "The more opulent citizens take great care not to stand aloof from the people," wrote Alexis de Tocqueville, the great chronicler of American democracy, in the 1830s. "On the contrary, they constantly keep on easy terms with the lower classes: They listen to them, they speak to them every day."

Americans love...