In the wake of [the Supreme Court’s Obergefell] decision, all parties agreed that the Commonwealth’s ban on same-sex marriage was unconstitutional. We agreed, vacated the judgment, and remanded. On remand, the district court nevertheless denied the parties’ joint request that the court enter judgment in favor of Petitioners. Instead, the court issued a memorandum concluding that the Commonwealth’s ban was not unconstitutional because, the district court claimed, the “right to same-sex marriage” has not been determined to apply in Puerto Rico. . . .

The district court’s ruling errs in so many respects that it is hard to know where to begin. The constitutional rights at issue here are the rights to due process and equal protection, as protected by both the Fourteenth and Fifth Amendments to the United States Constitution. Those rights have already been incorporated as to Puerto Rico. Examining Bd. Of Eng’rs, Architects & Surveyors v. Flores de Otero, 426 U.S. 572, 600 (1976). And even if they had not, then the district court would have been able to decide whether they should be. See Flores de Otero, 426 U.S. at 590.

In any event, for present purposes we need not gild the lily. Our prior mandate was clear:

In ruling that the ban is not unconstitutional because the applicable constitutional right does not apply in Puerto Rico, the district court both misconstrued that right and directly contradicted our mandate. And it compounded its error (and signaled a lack of confidence in its actions), by failing to enter a final judgment to enable an appeal in ordinary course.

Error of this type is not so easily insulated from review. This court may employ mandamus jurisdiction when a district court has misconstrued or otherwise failed to effectuate a mandate issued by this court.

Accordingly, Respondents’ motion to join in the petition for writ of mandamus is granted, the petition itself is also granted, and the case is remitted to be assigned randomly by the clerk to a different judge to enter judgment in favor of the Petitioners promptly, and to conduct any further proceedings necessary in this action.