Commentary  Dr. Peter H. Schuck, professor emeritus at Yale University, wrote in his book, “One Nation Undecided: Clear Thinking about Five Hard Issues That Divide Us,” that “the family is the essential core of any society, and the steady decline of two-parent households is probably the single most consequential social trend of the half-century.” I reflected upon those words as I read about the recent U.S. Census Bureau figures on the further decline of the American family. According to the 2021 Current Population Survey’s Annual Social and Economic Supplement, the percentage of adults living with a spouse decreased from 52 percent to 50 percent over the past decade, while the number of adults living alone increased to 37 million, up from 33 million in 2011—28 percent of all U.S. households. The statistics get even more sobering: 34 percent of adults over the age of 15 have never been married, compared …