Q: Are there any federal legal rights that can be enforced by private individuals only by bringing suit in state court?
A: Private actions under the Telephone Consumer Protection Act (Act), 47 U.S.C.S. § 227 (the "junk fax" law), can be brought only in state court. See Consumer Crusade, Inc. v. Affordable Health Care Solutions, Inc., 121 P.3d 350 (Colo. App. 2005).
Deeper significance: It reminds us that while District Courts have federal question jurisdiction, that Congress has wide discretion to provide that federal laws may be enforced solely in state court. (The deeper question of whether all federal courts can be denied jurisdiction over a federal question, i.e. whether even Supreme Court certiorari review can be eliminated in such a case, is less settled.)