City of Los Angeles v. County of Kern

Though federal court jurisdiction is constrained by article III of the United States Constitution principally to claims presenting a federal case or controversy or disputes between diverse parties, federal courts may assume supplemental jurisdiction over related state claims that “form part of the same case or controversy.” ( 28 U.S.C. § 1367 (a); see Mine Workers v. Gibbs (1966) 383 U.S. 715, 725 [ 16 L.Ed.2d 218 , 86 S.Ct. 1130 ] [federal jurisdiction extends to state claims that share “a common nucleus of operative fact” with a federal claim].) The assumption and retention of supplemental jurisdiction are not mandatory; inter alla, if the federal basis for jurisdiction dissolves but supplemental claims remain, the federal court may dismiss them, leaving them to be refiled in state court. (§ 1367(c)(3); see Jinks v. Richland County (2003) 538 U.S. 456, 459 [ 155 L.Ed.2d 631 , 123 S.Ct. 1667 ].) Congress has spelled out the consequences for statute of limitations purposes of such a state claim journey into federal court: the limitations period is “tolled while the claim is pending and for a period of 30 days after it is dismissed” absent a state rule extending the period…