Sonner v. Premier Nutrition Corp.

[The court which issued the prior judgment has] a strong presumption against enjoining a state court proceeding, as determining the preclusive effect of a prior judgment “is usually the bailiwick of the second court.” Smith v. Bayer Corp., 564 U.S. 299, 307 (2011).

 In District Court, putative class Plaintiff-Appellee’s claims were dismissed for failure to state a claim. Sonner v. Premier Nutrition Corp. (Sonner I), 971 F.3d 834 (9th Cir. 2020). Plaintiff-Appellee immediately refiled in state court; Defendant-Appellant returned to the District Court seeking a permanent injunction of the state court proceedings under the “relitigation exception” to the Anti-Injunction Act. 18 U.S.C. § 2283. There is a strong presumption against enjoining a state court proceeding, as determining the preclusive effect of a prior judgment “is usually the bailiwick of the second court.” Smith v. Bayer Corp., 564 U.S. 299, 307 (2011). Determining the outcome of a res judicata analysis here does not matter to the outcome of this appeal. The District Court below correctly determined § 2283 allows an injunction but does not require one. Although at least two of the three elements of a res judicata were met, serious doubts arose as to the application of state or federal common law. Every doubt should be resolved in favor of denying an injunction. Smith, 564 U.S. at 306. As res judicata can be raised as a defense in the second court, the state court here, the District Court properly denied the injunction. Affirmed.