Tomorrow, the Supreme Court will hear oral arguments in Obergfell v. Hodges, the long-awaited case addressing the constitutionality of laws restricting marriage to opposite-sex couples. In this post, I summarize and link some previous Volokh Conspiracy posts on the important issues at stake in tomorrow’s argument. While I focus primarily on posts I have written myself, that is in no way meant to denigrate the important contributions of my co-bloggers. Some of them will likely provide their own thoughts on tomorrow’s argument, and will surely do a better job of conveying their views than I could.

Most experts expect a majority of the Court to rule in favor of a constitutional right to same-sex marriage (an assessment I share). If that expectation turns out to be correct, the justices will have to choose between several different possible rationales for such a result. Which one they select may have important implications for future cases, and for constitutional theory. I summarize the possible alternatives and their potential impact in this post. In a more recent post, I described how several of these theories played a role in the recent Ninth Circuit case striking down laws banning same-sex marriage.

One of the most important things to look for in tomorrow’s argument is which of these theories the justices seem interested in. If, as many expect, the case ends up being decided by a narrow 5-4 margin, it is possible that the majority will be divided between adherents of two or more different approaches.

Many of my own writings on same-sex marriage have focused on the sex discrimination argument for striking down laws banning it. This issue is the focus of the amicus brief I coauthored with Northwestern law professor Andrew Koppelman on behalf of an ideologically diverse group of legal scholars. We summarized our argument in a recent USA Today op ed. I first laid out my take on the sex discrimination issue in a 2012 post. Several lower court judges have recently endorsed the sex discrimination theory, which may give this previously somewhat neglected argument some added momentum.

In recent months, an extensive debate has arisen over whether a right to same-sex marriage is compatible with originalist approaches to constitutional interpretation. I summarized the various originalist arguments for same-sex marriage in this post, which led to an exchange with co-blogger Orin Kerr (see here for the last post in the debate, which contains links to earlier ones). Andrew Koppelman and I outlined the originalist case for the sex discrimination argument on pp. 23-28 of our amicus brief. In this post, I addressed Justice Antonin Scalia’s famous question asking when did it become unconstitutional to exclude homosexual couples from marriage?” It turns out that an originalist rationale for a right to same-sex marriage (or any other right) doesn’t necessarily require a precise answer.

Co-blogger Dale Carpenter has been a leading commentator on constitutional issues relating to gay rights for many years. In this recent post, he offered an insightful assessment of the potential impact of a Supreme Court decision endorsing a right to same-sex marriage. Dale has also written an important analysis of the “animus” rationale for striking down laws banning same-sex marriage, which is one of the more likely paths that the Supreme Court might take. While I do not share Dale’s enthusiasm for the animus theory, his article is the most thorough and sophisticated analysis of this doctrine.

The lower court decision being reviewed by the Supreme Court is the recent Sixth Circuit ruling upholding laws banning same-sex marriage, authored by prominent conservative Judge Jeffrey Sutton. I critiqued Sutton’s opinion in this post.

The Supreme Court’s 2013 decision in United States v. Windsor, which invalidated part of the Defense of Marriage Act, unquestionably set the stage for the present case. In a post written soon after Windsor came down, I explained why the ruling provided a boost for supporters of a right to same-sex marriage, despite the mixed and ambiguous nature of its reasoning. Some of that reasoning may have been influenced by an amicus brief submitted by several constitutional federalism scholars, including VC bloggers Randy Barnett, Dale Carpenter, and myself, which Justice Anthony Kennedy cited in his majority opinion. I discussed the role of federalism considerations in the Windsor decision in this post.

Finally, the pro-same-sex marriage movement is another in a long line of efforts to use litigation as part of a broader strategy for achieving constitutional and political change. Previous examples include the abolitionists, the civil rights movement, the women’s rights movement, and – more recently – movements seeking to protect gun rights and property rights. There is a longstanding debate among legal scholars and political scientists about whether litigation is an effective tool for such movements, or whether it is a dangerous diversion that actually reduces their odds of success. In a series of posts written in 2008 and 2009, I argued that same-sex marriage litigation has given a major boost to the gay rights movement, and that this success has important implications for our understanding of the role of judicial review in effecting change more generally. At the time, some prominent commentators argued that the political backlash against early state court decisions endorsing same-sex marriage proved the validity of the opposite position in the longstanding debate over the efficacy of judicial review.

I think the events of the last five years provide strong support for my position. But it may be too early to reach any definitive conclusions on this subject. It is hard to take an objective historical perspective on a controversy that is still ongoing, and still generates strong emotions on both sides. The one thing that can be said with some certainty is that tomorrow’s argument and the resulting Supreme Court decision will be important milestones in the history of both the Court and the gay rights movement.