The Simmering Debate Over Supplemental Jurisdiction

In this essay, Professor Pfander revisits the debate surrounding supplemental jurisdiction under 28 U.S.C. § 1367, specifically, § 1367’s effect on Zahn v. International Paper Co. The Supreme Court held in Zahn that a federal court, sitting in diversity, may not exercise supplemental jurisdiction over claims by unnamed members of a plaintiff class that fail to satisfy the amount-in-controversy requirement. One account of § 1367 is that the statute overruled Zahn’s restrictive view of supplemental jurisdiction. An alternative account, adopted by the Tenth Circuit in Leonhardt v. Western Sugar Co., is that the statute preserves Zahn’s prohibition. Recent decisions by the Fourth and Ninth Circuits deepen a circuit split on the question, perhaps increasing the likelihood that the Supreme Court will address the question. <br><br>Professor Pfander defends the Leonhardt account. After providing a brief overview of the interpretive issues, Professor Pfander considers and rejects a variety of criticisms of the Tenth Circuit’s approach that have appeared in recent decisions. This thoughtful essay offers the reader a textually credible account of § 1367 that squares with what Congress expected the statute to accomplish and refrains from unsettling the many jurisdictional distinctions that had emerged before the codification of supplemental jurisdiction.