I recall arguing and arguing that marriage is special because the whole of society depends on its strength and integrity; and I recall my gay friends rolling their eyes and pointing to statistics about heterosexual marriage—statistics on fornication, on out-of-wedlock births, on domestic abuse, on adultery, and on divorce—and letting them speak for themselves. Straight people have not made a good case for marriage. We, as a nation, have not behaved as if it’s worth preserving.