Indeed, the 14th Amendment’s equal protection clause establishes a broad assurance of equality for all. It guarantees the same rights under the law for all men and women of any race, whether rich or poor, citizen or alien, gay or straight, and, as the court held in The Civil Rights Cases (1883) “prohibits any state legislation which has the effect of denying to any race or class, or to any individual, the equal protection of the laws.” As the provision’s proponents said in their congressional debates in 1866, the clause “establishes equality before the law” and “abolishes all class legislation in the States,” thereby “securing an equality of rights to all citizens of the United States, and of all persons within their jurisdiction.”
Under the 14th Amendment, the court ruled in Romer, a state can’t relegate anybody to the status of a pariah, “a stranger to its laws” — or deny to gay men or lesbians rights basic to “ordinary civic life in a free society” so as to “make them unequal to everyone else.” The equal protection clause, the court said in Windsor, clearly protects against state‐sponsored discrimination and “withdraws from Government the power to degrade or demean.”
Nevertheless, the 6th U.S. Circuit Court of Appeals — when it heard the cases now at issue — held that the equal protection clause doesn’t apply to state marriage laws because there’s no evidence that “the people who adopted the Fourteenth Amendment understood it to require the States to change the definition of marriage.”
The lower court erred by focusing on a certain kind of original understanding— the immediate effect supporters “understood” the 14th Amendment to have. The Supreme Court has rejected that approach, focusing instead on original meaning. Look no further than the remarkable Second Amendment case of District of Columbia v. Heller, where both the majority and dissenting opinions reasoned on originalist grounds.
In the 14th Amendment context, the court has asked how the well‐established meaning of terms added to the Constitution in 1868 applies to modern exclusions of new social groups. It has described the equal protection clause as securing to all “the protection of equal laws” and prohibiting caste legislation that discriminates against a social class.
Indeed, many equal‐protection precedents are hard to explain as a matter of “original understanding” but are amply justified as an application of the equality‐under‐law concept. The rule against class legislation applies with special force to the central institutions of state law, as the court has repeatedly held in striking down laws that restricted marriage licenses based on incarceration, owing child support, or race.
So while it’s undoubtedly true that nobody in 1868 expected that the 14th Amendment would force a state to license same‐sex marriages, evidence of the ratifying generation’s prophetic anticipation isn’t necessary for courts to apply the provision to novel facts. As originalist scholar Ilya Somin recently put it, original‐meaning originalism “is entirely consistent with updating the application of its fixed principles in light of new factual information. Indeed, such updating is often not only permitted, but actually required by the theory. Otherwise, it will often be impossible to enforce the original meaning under conditions different from those envisioned by the generation that framed and ratified the relevant provision.”
Just as a “19th‐century statute criminalizing the theft of goods is not ambiguous in its application to the theft of microwave ovens,” as Justice Antonin Scalia wrote in the otherwise forgettable case of K Mart Corp. v. Cartier Inc. (1988), a 19th‐century constitutional command that no state may “deny to any person within its jurisdiction the equal protection of the laws” isn’t ambiguous in its application to sweeping exclusions in state family law. The civil recognition of marriage is a legal matter and the plaintiffs here have clearly been denied myriad legal benefits and protections solely on account of their sexual orientation. This is the very kind of class‐based discrimination that the equal protection clause prohibits.
In short, does the 14th Amendment require states to issue marriage licenses to same‐sex couples? Of course not. It doesn’t say a word about marriage licenses. Or driver’s licenses. Or liquor licenses, business permits, corporate status, public schools, libraries, buses or universities.
The 14th Amendment requires almost nothing affirmative. The only benefits states must grant are the privileges or immunities of citizenship, the due process of law (before depriving someone of life, liberty, or property), and the equal protection of the laws. In other words, the 14th Amendment requires states to issue marriage licenses to same‐sex couples only if they give them to everyone else.