Exxon Mobil Corp. v. Allapattah Services, Inc., 545 U. S. _____, 125 S. Ct. 2611, 2005 WL 1469477 (June 23, 2005).
In this case, the United States Supreme Court said “yes” to the question of whether a court sitting in diversity may exercise supplemental jurisdiction under 28 U.S.C. §1367 over plaintiffs who do not meet the amount in controversy requirement. In a paragraph near the end of the opinion, Justice Kennedy, writing for the Court, noted that the Class Action Fairness Act does not come into play in the Court’s analysis of §1367, given that (a) the new law is not retroactive, and (b) cases involving supplemental jurisdiction under §1367 might not necessarily fall under CAFA’s umbrella. The underlying cases reviewed by the Supreme Court from the First and Eleventh Circuits each predated CAFA.

Justice Kennedy explained: “The CAFA, moreover, does not moot the significance of our interpretation of § 1367, as many proposed exercises of supplemental jurisdiction, even in the class-action context, might not fall within the CAFA’s ambit. The CAFA, then, has no impact, one way or the other, on our interpretation of § 1367.”