We've all heard that, in the United States v. Windsor, the Supreme Court just declared Section 3 of the Defense of Marriage Act (DOMA) unconstitutional.  In part, Section 3 stated that any mention of "marriage" in federal laws, rules, and regulations referred only to a union between one man and one woman.  Thus, Section 3 prevented homosexual couples from enjoying many federal perks, such as tax credits for having children.

Writing for the majority, Justice Anthony Kennedy said, "DOMA is unconstitutional as a deprivation of the liberty of the person [to enjoy federal perks] protected by the Fifth Amendment of the Constitution."  The Fifth Amendment reads in part as follows: "No person shall be ... deprived of ... liberty ... without due process of law."

Kennedy's decision partially relieved Jennifer Marshall of the Heritage Foundation, who noted the following:

The important news you may not be hearing [about Windsor] is that the U.S. Supreme Court did not redefine marriage across the nation. That means the debate about marriage will continue. States are free to uphold policies recognizing that marriage is the union of a man and a woman, so that children have a mother and a father.

However, Marshall may be unaware of the craftiness of Kennedy's decision.  At the Volokh Conspiracy, Orin Kerr recently discussed how, given certain language in Kennedy's decision, the Supreme Court could soon declare a constitutional right to same-sex marriage:

[In Windsor,] the Supreme Court punted on the basic question of whether there is a constitutional right to same-sex marriage. ... [However,] [t]here's lots of language in Windsor strongly hinting that a majority of the current Court would (eventually) hold that such a right exists. ... So the issue may be back on the Supreme Court's docket in just a few years. And at least based on Windsor, it seems more likely than not that the votes will be there (assuming no change in personnel) to hold that there is a constitutional right to same-sex marriage.

Kerr's article provided no examples of Windsor's language that suggest that the Constitution contains a right to same-sex marriage.  However, recently in The Atlantic Garrett Epps made an argument similar to Kerr's.  Epps noted that a future Supreme Court could use the following rationale in Windsor to invalidate states laws promoting traditional marriage (substitute the words "state laws promoting traditional marriage" for the word "DOMA"): 

[DOMA] operates to deprive same-sex couples of the benefits and responsibilities that come with the ... recognition of their marriages. This is strong evidence of a law having the purpose and effect of disapproval of that class. The avowed purpose and practical effect of the law here in question are to impose a disadvantage, a separate status, and so a stigma upon all who enter into same-sex marriages[.] ... [DOMA's] ... principal purpose is to impose inequality[.] ... [DOMA] tells those couples, and all the world, that their ... marriages are unworthy of ... recognition. This places same-sex couples in an unstable position of being in a second-tier marriage. The differentiation demeans the couple, whose moral and sexual choices the Constitution protects[.]

Epps further noted that Kennedy even invoked the Fourteenth Amendment, which says "no state [emphasis added] shall ... deny to any person within its jurisdiction the equal protection of the laws," as follows:

The liberty protected by the Fifth Amendment's Due Process Clause contains within it the prohibition against denying to any person the equal protection of the laws. While the Fifth Amendment itself withdraws from Government the power to degrade or demean in the way this law does, the equal protection guarantee of the Fourteenth Amendment [emphasis added] makes that Fifth Amendment right all the more specific and all the better understood and preserved.

Thus, in Windsor, Kennedy laid the groundwork for invalidating state laws promoting traditional marriage as violations of the Fourteenth Amendment's guarantee that "no state shall ... deny to any person [homosexual] ... the equal protection of ... [marriage] laws."  Future Kennedy may declare that, if states want to grant marriage licenses and confer such state perks to married couples as tax breaks for having children, then states must recognize same-sex marriage. 

Marshall's above claim that Windsor "did not redefine marriage across the nation" is correct.  However, the writing is on the wall, and state laws promoting traditional marriage appear doomed.  What will states do if forced to recognize same-sex marriage?  Exit the marriage business and abolish state perks tied to marital status?  Or, given the potential problems of privatizing marriage, will states just comply with future Kennedy's decision?

Daniel Smyth is co-founder and editor of LibertyBlog.org. Follow him on Twitter at @DanielSmyth7.