Fifteen states have filed an amicus brief in support of the federal Defense of Marriage Act (DOMA), urging the Supreme Court to review an appellate court panel’s decision striking down the law.

Passed by broad bipartisan majorities and signed by President Clinton in 1996, DOMA defines marriage as between one man and one woman for the purposes of federal law and ensures that states do not have to recognize same-sex marriages entered into in states that have redefined the institution.

Like all congressionally passed laws, DOMA should be vigorously defended in court by the U.S. Department of Justice. That’s not the case here. Instead, in an extraordinary move, the Obama Administration first undermined, and then abandoned completely, its defense of DOMA. The House of Representatives was forced to step in and provide a defense of DOMA in this and numerous other cases challenging the statute.

The states’ brief in Bipartisan Legal Advisory Group v. Gill is highly critical of a First Circuit Court of Appeals panel’s decision to invalidate the section of DOMA dealing with the federal marriage definition. That decision disregards binding Supreme Court precedent that would have foreclosed the challenge. It also invents a novel standard of judicial review to justify striking down an act of Congress in favor of the court’s own policy preferences.

The implications of the panel’s decision are troubling. The federal government differentiates between marriage and other relationships on the basis of their capacity for procreation. This differentiation is, according to the First Circuit panel’s reasoning, constitutionally illegitimate.

As the 15-state brief argues, this procreative rationale is a critical factor in the marriage laws in some 42 states. If the First Circuit’s rationale striking DOMA on federal constitutional grounds is allowed to stand, the brief argues, it could threaten other marriage laws: “It requires no great leap of logic to conclude that a judicial declaration that DOMA serves no legitimate government purpose erodes the constitutional support for similar state laws.”

As the building block for the rest of society, marriage’s central civic purpose has always been to connect biological parents—especially fathers—to their children. As the states’ brief argues, civil recognition of marriage “historically has not been based on a state interest in adult relationships in the abstract.” Rather, “traditional marriage and benefit policies further state interests in responsible procreation by encouraging biological parents to remain together, a rationale that cannot extend to same-sex couples.”

The institution’s meaning is thus integrally linked to the social needs it is designed to address. “A constitutional doctrine that requires the same benefits for same-sex and opposite-sex couples must supply a coherent rationale for government recognition of both, not simply attack traditional marriage as antiquated or somehow ill-considered,” the brief concludes.

A federal district court in Hawaii has declined to adopt the First Circuit panel’s reasoning and upheld that state’s definition of marriage as one man and one woman. In so doing, it bucked the all-too-common trend of courts short-circuiting democratic processes by judicial decree.