In Obergefell v. Hodges, Justice Kennedy holds that bans on same-sex marriage violate both the Due Process Clause and the Equal Protection Clause. His equal protection analysis does not discuss the standard doctrinal tiers of scrutiny. He does not hold that restricting marriage to opposite-sex couples violates sex equality, as some amici proposed. He does not hold that sexual orientation is a suspect classification, as the Obama Administration urged the Court to do. He does not suggest that limiting marriage to opposite-sex couples involves unconstitutional animus, as he did in Windsor; nor does he say that the ban fails "rational basis with a bite," because it is premised on irrational prejudice.
At the very end of the opinion there is language that suggests that the exclusion of gay couples would violate even the ordinary rational basis standard, because the only justification that the state could come up with--banning gays from marrying will encourage straights to marry--makes no sense: "it is unrealistic to conclude that an opposite-sex couple would choose not to marry simply because same-sex couples may do so." Yet Kennedy does not argue that the exclusion violates rational basis.
Even so, Kennedy's argument for treating same-sex marriage as part of the fundamental right to marry has many significant equality ideas. He states that "[t]here is no difference between same- and opposite sex couples with respect to" marriage's usefulness in grounding the social order. He argues that excluding same-sex couples "teaches that gays and lesbians are unequal in important respects." and that "[i]t demeans gays and lesbians for the State to lock them out of a central institution of the Nation's society." He adds that "laws excluding same-sex couples from the marriage right impose stigma and injury of the kind prohibited by our basic charter."
As in Lawrence v. Texas, the language of stigma and demeaning sounds in civil equality, and the anti-subordination principle. Indeed, later in the opinion, Kennedy says:
"the challenged laws abridge central precepts of equality. . . . [they are] essentially unequal: same-sex couples are denied all the benefits afforded to opposite-sex couples and are barred from exercising a fundamental right. Especially against a long history of disapproval of their relationships, this denial . . . works a grave and continuing harm. The imposition of this disability on gays and lesbians serves to disrespect and subordinate them. And the Equal Protection Clause, like the Due Process Clause, prohibits this unjustified infringement of the fundamental right to marry."
If this sounds like an anti-subordination rationale, that is because it is. And together with other parts of the opinion, Kennedy is carefully laying the groundwork for arguing that gays and lesbians have suffered a long history of discrimination, and that they are excluded from important opportunities for reasons that have nothing to do with their contribution to society. (In fact, at one point, Kennedy even suggests that sexual orientation is akin to an immutable characteristic, arguing that the “immutable nature [of same-sex couples] dictates that same-sex marriage is their only real path to this profound commitment [of marriage].”) Add to all this the point that gays and lesbians are a minority without significant representation in "the Nation's decision-making councils," and you have a pretty good argument for treating sexual orientation as a suspect classification. And in fact, this is what the Obama Administration urged the Court to do in Obergefell. Nevertheless, having set up virtually all of the elements for this conclusion, Kennedy does not go there.
Instead, Kennedy's equal protection argument seems to be that equality and liberty are two sides of a coin-- that they are two different perspectives on a problem that shine light on each other: "Each concept-- liberty and equality-- leads to a stronger understanding of the other." Hence selective denials of fundamental rights deny equal dignity. Accordingly, Justice Kennedy, in an extremely interesting passage, reinterprets the sex equality cases of the 1970s as protecting the equal dignity of men and women in the right to marry (slip op. at 20-21).
Kennedy's account of equality is perhaps closest to two ideas in previous jurisprudence. The first is in Casey and in Justice Ginsburg's dissent in Carhart II. Both opinions are officially about the liberty protected by the Due Process Clause, but both argue that the women's interest in reproductive liberty is tied to their equal status as citizens. We could read Obergefell, together with Lawrence, as drawing on and expanding these ideas of liberty as equal citizenship status (although, interestingly the abortion cases are never mentioned in the majority opinion).
The second idea comes from Skinner v. Oklahoma and from some of the Warren Court's decisions on the rights of the poor, especially Harper v. Virginia Board of Elections. This is the "fundamental rights" strand of equal protection doctrine. The government violates equal protection when it discriminates against or selectively burdens the exercise of a fundamental right or interest. We could read Obergefell as part of this line of cases. Because marriage is a fundamental right (or more correctly, a fundamental interest, as I discuss below), the state cannot deny the right to marry arbitrarily to a group of citizens without a compelling interest. Here the state does not even have a reasonable justification, so, a fortiori, the discrimination is unconstitutional.
Justice Thomas objects to the use of dignity language. He argues first, that term "dignity" does not appear in the Constitution. Second, he argues that dignity is innate and that no man-made institution can take away this dignity. Even the inherent dignity of slaves, he argues, could not be taken away by the vicious institution of slavery. But Thomas is not really engaging with Kennedy's argument. Of course, Kennedy might respond, Thomas is correct that human dignity is innate and cannot be taken away by the state. That is precisely why the Constitution values it. But when the state fails to accord people the equal concern and respect that they deserve (to quote Ronald Dworkin's famous phrase), this violates the Equal Protection Clause of the Constitution. Recognizing and respecting dignity is not the same thing as creating dignity or being the source of dignity, any more than respecting religious freedom is the same thing as creating religion.
Moreover, although the term "dignity" does not appear in the Constitution, the term "equal protection" does appear, and the point of the Equal Protection Clause is to require the state to show equal concern and respect toward human beings. This requires the state to recognize the equal dignity of all persons who are subject to its jurisdiction.
The best version of Kennedy's argument is not that the state creates dignity or can take it away. Rather, it is that the state has an obligation to respect and recognize the inherent dignity of the people who live within its borders. The state violates this obligation when it fails to accord people equal respect and concern. One way that states might do this is to arbitrarily deny a host of rights and benefits that come with marriage to a class of its citizens. Although the state may not have to provide those rights and benefits in the first place, once it has given them out, it may not make arbitrary distinctions in who receives them.
Justice Thomas argues that the liberty of citizens is fully protected when they participate in democratic self-government. But even he would agree that some fundamental rights are necessary to protect human liberty from democratic majorities (Think Citizens United, which also protects the non-human liberty of corporations!). So Thomas and Kennedy simply disagree about what those liberties are and whether they can be found in the Constitution. Thomas objects that there is no "Dignity Clause" in the Constitution. Nevertheless, "equal protection," like "freedom of speech," actually does appear in the Constitution's text. (Thomas himself is happy to remind us of that fact in every affirmative action case.) Indeed, so do the words "Privileges or Immunities," which Thomas correctly pointed out in McDonald, do guarantee some substantive rights against democratic abridgement.
I've reconstructed the best version of how Kennedy would respond to Justice Thomas's points about dignity. This response, however, suggests an important point. It may be better to call marriage a fundamental interest than a fundamental right.
The difference is that the state does not have to provide a fundamental interest at all, but once it does, it must bestow and protect it equally among the members of the political community. Thus, the state does not have to have a bundle of rights called marriage. The state could simply allow private marriage ceremonies and enforce civil contracts between couples. (Note that I am not recommending this solution, which has its own problems.) Nevertheless, once the state creates a bundle of legal rights and calls it "marriage," it cannot arbitrarily decide who can enjoy that bundle of rights.
Why did Kennedy not use the existing features of equal protection law? There are many possible reasons. First, as a libertarian, Kennedy may simply be more comfortable talking about liberty. Second, Kennedy might not want to take on all of the legal consequences of creating a new suspect classification-- the first since the 1970s--without more consideration about the consequences for legal doctrine in a host of different areas. Third, Kennedy may not be particularly enamored of the formalism of existing equal protection categories, which in many cases tend to obscure the real issues at stake.
Finally, perhaps Kennedy did not want to employ the "rational basis with a bite" or "animus" lines of cases because he did not think that he could easily show that all of these state laws defining marriage in terms of opposite-sex couples were passed because of malice or irrational prejudice against gays and lesbians. If he declared that all of them were based in animus, he would be declaring all of the people who voted for them had bad intentions or were prejudiced, or both. Instead, he simply states that whatever their motivations, the laws they produced had the effect of demeaning and subordinating gays and lesbians.
Is this an important difference? Will it make the decision more acceptable to more people? It is hardly clear that it will. After all, most citizens never read Supreme Court opinions. And opponents of the decision already feel plenty offended by it.
When we examine it closely, Kennedy's opinion does have a lot of equality ideas in it. But it does not offer a very clear account of where doctrine is supposed to go from here. That may be deliberate. But it will mean that the lower courts will have to spend a lot of time puzzling out how best to apply Kennedy's arguments to a host of other issues, including, for example, state discrimination in adoption, family formation, employment, housing, and education. Those are the next stages in the struggle for equality for sexual orientation minorities.