What is one reason a court may decline to exercise supplemental jurisdiction?

One reason a court may decline to exercise supplemental jurisdiction is when the original claims are dismissed. Under 28 U.S.C. § 1367, a court has the discretion to decline to exercise supplemental jurisdiction over state law claims if the federal claims are dismissed early in the proceedings. This is particularly relevant when the federal court has not engaged significantly in the case and continued jurisdiction over the state claims could lead to inefficiency and judicial resource concerns.

This practice aligns with the principle that federal courts are typically responsible for federal law issues, and if the federal claims—often the basis for the court's jurisdiction—are no longer in play, then the court may find it more appropriate to leave the state law issues to the state courts. Thus, the court is prioritizing federalism and promoting judicial efficiency by avoiding unnecessary adjudication in areas of law that state courts are fully competent to handle.