Yesterday the Supreme Court issued a unanimous decision in Smith v. Bayer Corp. (09-1205), a case covered earlier here. The decision reverses the 8th Circuit.
Justice Kagan’s opinion begins:
In this case, a Federal District Court enjoined a state court from considering a plaintiff’s request to approve a class action. The District Court did so because it had earlier denied a motion to certify a class in a related case, brought by a different plaintiff against the same defendant alleging similar claims. The federal court thought its injunction appropriate to prevent relitigation of the issue it had decided.
We hold to the contrary. In issuing this order to a state court, the federal court exceeded its authority under the “relitigation exception” to the Anti-Injunction Act. That statutory provision permits a federal court to enjoin a state proceeding only in rare cases, when necessary to “protect or effectuate [the federal court’s] judgments.” 28 U. S. C. §2283. Here, that standard was not met for two reasons. First, the issue presented in the state court was not identical to the one decided in the federal tribunal. And second, the plaintiff in the state court did not have the requisite connection to the federal suit to be bound by the District Court’s judgment.
Justice Thomas joined only Parts I and II-A of the opinion.