After accepting an appeal in the case of Hollingsworth v. Perry, over California's Proposition 8 and whether the state can, should, or must license same-sex couples as marriage, the United States Supreme Court not only declined to reach the merits of the appeal, but found that the Ninth Circuit federal court of appeals was without jurisdiction to hear an appeal from Judge Vaughan Walker's order, requiring California to do so.
The practical effect is that there is no mandatory federal precedent asserting that any provision or interpretation of the federal constitution requires any state to redefine marriage to include same-sex couples. Judge Walker's order remains valid, in California. All appellate circuits, and all federal district courts, remain free to consider the merits of any arguments that may be presented from time to time. State courts outside of California are free to do the same.
There is no way to know what was on the minds of justices who refuse for procedural reasons to make a decision on the merits of a case. Perhaps some justices had this in mind all the time, when agreeing to hear the case. Perhaps not. If the Supreme Court had not taken the case at all, the Ninth Circuit ruling would have been mandatory precedent in the western states where it has jurisdiction, but nowhere else. It would have been available as persuasive authority for any court elsewhere to take note of.
The division of the court did not follow a strict split between those usually referenced as "liberals" or "conservatives." Chief Justice Roberts wrote the majority opinion, joined by justices Scalia, Ginsburg, Breyer, and Kagan. Justice Kennedy dissented, joined by justices Thomas, Alito and Sotomayor. Whether any justice supported dismissing the case because they feared their preferred position couldn't win, or favored taking the case confident their preferred position would prevail on the merits, can only be the subject of speculation.
The clock has been reset, and the debate will continue for the forseeable future. The Ninth Circuit had declined to rule on whether defining marriage as the union of a man and a woman denies to individuals with a homosexual orientation the equal protection of the laws. Instead, it ruled that once California had extended marriage licenses to same-sex couples, it could not then take it back without engaging in unconstitutional discrimination against a disfavored group. That ruling is now vacated.
The procedural history that guided the court's decision turns on the fact that the governor and attorney general of California declined to defend Proposition 8 in court. Proposition 8 was a constitutional amendment, that defined marriage as limited to the union of a man and a woman, adopted by referendum. With several same-sex couples who wanted marriage licenses challenging the amendment in federal court, all state officials named as defendants endorsed the plaintiffs' position. According to California law, the citizens committee that proposed the amendment is authorized to defend it in court if state officials decline to do so.
The Supreme Court ruled that under federal court rules and constitutional obligations, only state officials have standing to defend a state law, or constitutional provision, in court. Therefore, no appeal should have been accepted in the first place by the Ninth Circuit.
This tears a gaping hole in the purpose of allowing for popular referenda. As Justice Kennedy wrote in dissent, "the very object of the initiative system is to establish a law-making process that does not depend upon state officials." The very purpose is to "afford the people the ability to propose and to adopt constitutional amendments or statutory provisions that their elected public officials had refused or declined to adopt.”
The court has left no avenue for people, who prevail in a referendum in the teeth of opposition by their elected officials, to have the decision defended against a legal challenge. But that may not have been the primary consideration in this ruling. The decision was 5-4, so trained legal minds had no trouble coming to opposite conclusions.