From Smith v. Bayer Corp., 180 L. Ed. 2d 341 (2011):
[T]he "relitigation exception" to the Anti-Injunction Act ... 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, t ...
From Smith v. Bayer Corp., 180 L. Ed. 2d 341 (2011):
[T]he “relitigation exception” to the Anti-Injunction Act … permits a federal court to enjoin a state proceeding only in rare cases, when necessary to “protect or effectuate [the federal…