The Supreme Court handed down a unanimous per curiam decision this morning in Nitro-Lift Technologies v. Eddie Lee Howard. The Court ruled that an Oklahama Supreme Court's decision nixing contract provisions was a decision for an arbitrator (not the Oklahoma courts):
State courts rather than federal courts are most frequently called upon to apply the Federal Arbitration Act (FAA), 9 U. S. C. §1 et seq., including the Act’s national policy favoring arbitration. It is a matter of great importance, therefore, that state supreme courts adhere to a correct interpretation of the legislation. Here, the Oklahoma Supreme Court failed to do so. By declaring the noncompetition agreements in two employment contracts null and void, rather than leaving that determination to the arbitrator in the first instance, the state court ignored a basic tenet of the Act’s substantive arbitration law. The decision must be vacated.
Here's another key passage:
The state court reasoned that Oklahoma’s statute “addressing the validity of covenants not to compete, must govern over the more general statute favoring arbitration.” 273 P. 3d, at 26, n. 21. But the ancient interpretive principle that the specific governs the general (generalia specialibus non derogant) applies only to conflict between laws of equivalent dignity. Where a specific statute, for example, conflicts with a general constitutional provision, the latter governs. And the same is true where a specific state statute conflicts with a general federal statute.There is no general-specific exception to the Supremacy Clause, U. S. Const. Art. VI, cl. 2. “‘[W]hen state law prohibits outright the arbitration of a particular type of claim, the analysis is straightforward: The conflicting rule is displaced by the FAA.’” Marmet Health Care Center, Inc. v. Brown, 565 U. S. ___, ___–___ (2012) (per curiam)(slip op., at 3–4) (quoting AT&T Mobility LLC, supra, at ___–___ (slip op., at 6–7)). Hence, it is for the arbitrator to decide in the first instance whether the covenants not to compete are valid as a matter of applicable state law. See Buckeye, 546 U. S., at 445–446.
The Supreme Court also made quick work of the Oklahoma Supreme Court's odd assertion that its decision rested on independent and adequate state-law grounds. If that were correct — which is wasn't — the U.S. Supreme Court would have lacked power to review the Oklahoma court's ruling.