In Summers v. Earth Island Institute, decided in 2009, the U.S. Supreme Court granted certiorari with four questions presented. Number four has acute relevance today: "Whether the court of appeals erred in affirming the nationwide injunction issued by the district court." The Court didn't reach that question, however, because of its resolution of the other questions presented. But the Solicitor General's office did file a brief that addressed this question, with Paul Clement as the counsel of record. This brief is worth reintroducing to the discussion of the national injunction and the APA–especially now that there is such a lively scholarly debate about whether the APA codifies or creates a "universal vacatur" remedy.
(For new entrants into that debate on the APA, see this piece by Jonathan Adler, arguing no at the Notice & Comment blog of the Yale Journal on Regulation; and this piece for a Notre Dame Law review symposium by Ronald Levin, which argues that the APA is a framework statute, and its evolution is supposed to be guided by the courts, and the post-APA development of universal vacatur is one such salutary evolution.)
Here is the relevant section of the SG's brief in Summers v. Earth Island Institute:
