In Board of Educ. v. Dowell, 498 U.S. 237, 248, 111 S.Ct. 630, 637, 112 L.Ed. 2d 715, 728 (1991), the Court held that the lower courts erred in relying on Swift in refusing to vacate or modify a fully litigated desegregation order. Id. at 498 U.S. 246, 111 S.Ct. at 636, 112 L.Ed.2d at 728. Starting with the premise that school desegregation decrees are not intended to operate in perpetuity, the Court held that "Swift does not provide the proper standard to apply to injunctions" in such cases. Ibid.