William C. Duncan in National Review's The Corner blog:

Congress, represented by former solicitor general Paul Clement, has filed two briefs in one of the cases challenging the Defense of Marriage Act in a federal court in New York. One is a memorandum providing legal reasons the court should deny the ACLU’s motion for summary judgment. The second is a memorandum with reasons the court should grant the Bipartisan Legal Advisory Group’s motion to dismiss. Both are excellent, and I particularly appreciate the way the second brief explains the state’s interests related to procreation.

The opposition brief argues that “sexual orientation” is not analogous to race because, among other things, all federal circuit courts have rejected this idea, and gays and lesbians are not politically powerless (especially given that the state of New York and the federal government are supporting the ACLU position in the case). The brief also notes that the federal government has been involved in the definition of marriage in the past. A representative quote: “Plaintiff appears oblivious to the irony of maintaining that homosexuals have limited political power in a case in which her position is supported by both the State of New York and the United States Department of Justice. In light of the latter’s longstanding duty to defend the constitutionality of federal statutes, its decision to decline to defend the constitutionality of DOMA, and instead adopt the very position advocated by Plaintiff, is particularly telling.”

The memo supporting the motion to dismiss makes the foundational argument that DOMA is entirely consistent with constitutional guarantees. It argues that same-sex marriage is not a fundamental right deeply rooted in history and tradition, and that it does not discriminate on the basis of sex or sexual orientation. The brief also explains that Congress is justified by government interests in avoiding creation of “a social understanding that begetting and rearing children is not inextricably bound up with marriage” and in fostering marriages that provide mothers and fathers for children. It argues that any redefinition of marriage should be left to the democratic process. Representative quote: “Indeed, most sexually-active opposite-sex relationships have an inherent ability to produce children whether or not the spouses are seeking to do so at any given time. And the fact that opposite-sex relationships produce unplanned and unintended pregnancies is at the heart of society’s traditional interest in promoting the institution of marriage and providing incentives for these unplanned offspring to be raised in the context of a traditional family unit. Whatever else is true of the procreative potential of same-sex couples, the phenomena of unplanned and unintended pregnancies is limited to opposite-sex couples. Congress rationally could have concluded that a special legal category was necessary to recognize the special concerns that face a couple who must take account of this inherent possibility of their relationship, and to support and incentivize such relationships despite the increased responsibility they place upon the spouses.”