The U.S. Supreme Court fall term is young, but it has already heard three arguments in cases involving the Federal Arbitration Act, a likely sign of its continuing interest in fortifying arbitration and protecting it from meddling by courts and class actions.

But the two arguments aired Monday suggested the court’s pro-arbitration momentum still faces some obstacles, in the form of liberal justices who may be skeptical of arbitration’s omnipresence. The more conservative justices, including newly confirmed Brett Kavanaugh, asked far fewer questions.