A suit alleging legal malpractice in the handling of a patent case did not "arise under any Act of Congress relating to patents," 28 U.S.C. § 1338(a), so that the federal courts had exclusive jurisdiction over it, the Supreme Court held today. Indeed, Chief Justice Roberts’s opinion for the unanimous Court indicated that "state legal malpractice claims based on underlying patent matters will rarely, if ever, arise under federal patent law for purposes of § 1338(a)." Although the malpractice claim did require resolution of a patent-law question, that resolution was not—as precedent requires—"substantial" enough to require a federal forum. To be "substantial" for these purposes, a federal issue must be important to the federal system as a whole. In the case at bar, the patent-law question was "merely hypothetical": would the result in a particular infringement case have been different in the absence of attorney error? Nor was there any danger that allowing state courts to resolve these claims would undermine the uniform development of patent law.
Gunn v. Minton, S. Ct. No. 11-1118 (Feb. 20, 2013).