The amicus brief filed on behalf of Governor C. L. Otter of Idaho in the same-sex marriage case before the Supreme Court is remarkable for two reasons.  First, aside from Alabama Governor Robert Bentley and the governors who are named parties (and thus had no choice), he is the only sitting governor with the chutzpah to wade in before the Court on this controversial issue.

Second and more important, his brief establishes that state man–woman marriage laws pass any level of scrutiny the Court may throw at them.

The Court’s Three Levels of Scrutiny

Over the years, the Court has crafted three standards of review for laws subject to a claim of unconstitutionality under the Fourteenth Amendment. The most exacting standard—which applies, for example, to laws discriminating based on race or ethnicity—is called strict scrutiny, under which the Court will only uphold laws that help achieve a compelling government interest in the most narrowly tailored way. The government loses more often than it wins under this high constitutional bar.

Next is what is often called intermediate scrutiny, which the Court has applied to classifications based on sex. Here the Court will uphold laws that are substantially related to an important government interest.

The lowest level, which applies to other classifications, is whether the law is rationally related to a legitimate government interest. Laws almost always pass muster under this standard.

States’ Compelling Interest in Keeping the Man–Woman Definition of Marriage

The man–woman definition of marriage serves states and society in crucial ways.  Indeed, flowing from the institution of man–woman marriage are five social norms that especially benefit children, their mothers, society, and the state.

  1. Biological bonding and maintenance—that children deserve to be raised and supported by their biological parents—leads to a family structure that has been almost universally hailed as the gold standard for children’s flourishing.
  2. Gender diversity in parenting means a child will have a mother and a father, who together provide complementary but distinct benefits to a child’s social, emotional, intellectual and physical development.
  3. Procreation postponement emphasizes that children should not be conceived or brought into the world except within the stability of marriage.
  4. The norm affirming the social value of begetting and rearing children stems from the man–woman definition, which implicitly conveys the state’s encouragement of those procreation-related activities.
  5. Partner exclusivity encourages procreative sexual activity to occur only between spouses.

All of these norms are undergirded by a more general child-centricity norm that calls for parents to place their children’s needs and wants before their own.

The Consequences of Weakening or Destroying These Social Norms

Legally recognizing same-sex marriage sends a message from the state that dilutes or destroys these social norms and thus undermines their benefits to children and society. For instance, in moving to a genderless marriage regime where any two adults can marry, the law necessarily withdraws its endorsement of gender diverse parenting. The biological bonding norm is diminished since at least one if not both parents in a same-sex couple will not be the biological parent of the child.

The result will be fewer children raised in a home by their biological married mother and father. As social science has consistently demonstrated, this means more child poverty, poorer performance in school, more drug and alcohol abuse by youth, increased teen pregnancies and abortions, more behavioral and emotional problems, and more crime.

Not only will this lead to heartache and worse for these children and their families, but states will be left trying to pick up the pieces.  That is expensive.  And no number of programs or amount of spending can fix what is broken in the home.

In short, if a state does not have a compelling interest in preventing these problems and protecting children, there is no such thing as a compelling state interest.

Is Man–Woman Marriage Narrowly Tailored?

But a compelling interest isn’t enough under the Court’s tests of constitutionality. The law must also have a close fit to that interest, or, in the language of the law, be narrowly tailored. Same-sex marriage advocates have criticized man–woman marriage laws as not having this fit—largely because they allow infertile couples to marry.

But that’s just not a problem constitutionally. Allowing an infertile couple to marry still models man–woman marriage for the overwhelming percentage of couples who can procreate—thus strengthening, not undermining, the institution’s social norms.  Moreover, usually only one member of an “infertile couple” is infertile, so man–woman marriage still helps reduce extra-marital procreation. In any event, the “over-inclusiveness” point implicates only one of marriage’s social norms—procreation postponement—and has no effect on the others, all of which would be undermined by a genderless redefinition.

Moreover, once a few state judges began to interpret state constitutions to require same-sex marriage, states faced an all or nothing choice—either keep man–woman marriage with its host of benefits or risk having a genderless version that reduced or destroyed those benefits. For those states, then, expressly preserving the man–woman definition was their only, and best, option.

The Constitution Has No Qualms with the Man–Woman Definition of Marriage

Accordingly, however the Court wants to scrutinize man–woman marriage laws, they pass constitutional muster. The fact that in 2015 we are even having a debate as to whether the Constitution commands same-sex marriage is itself astounding. Fortunately, tradition, common sense, biology, social science, and the Constitution all agree that States can legitimately keep marriage to one man and one woman.