For diversity cases in class actions, what is the key consideration for SMJ?

In class action lawsuits involving diversity jurisdiction, the key consideration for subject matter jurisdiction (SMJ) is that the claims of the class representatives must meet the requirements for diversity. Specifically, this means that the representatives must be citizens of different states than the defendants in order for the federal court to have jurisdiction based on diversity.

When there’s a class action, the problem often revolves around whether it can be heard in federal court due to the parties' citizenship locations. If the class representatives do not meet the jurisdictional diversity requirements—with one being a citizen of the same state as any defendant—the case cannot be taken up in federal court under diversity jurisdiction, regardless of the citizenship of the other class members or the amounts they are claiming.

Indeed, while the class's overall claims must meet the amount in controversy requirement (which is typically $75,000 per individual claim in diversity cases), it's the representatives' citizenship that is crucial for establishing initial jurisdiction. Therefore, the emphasis is on the representatives’ diversity rather than that of every single class member, as the latter is not necessary to establish SMJ under diversity jurisdiction.