WASHINGTON – A victory for consumers and class action litigators seemed possible yesterday as the U.S. Supreme Court heard arguments in a high-stakes dispute over clauses that block class actions as a way of resolving contract disputes.

The justices seemed reluctant to second-guess a California court ruling that was the basis for deciding that such clauses are “unconscionable” under state law and cannot be enforced, even when they are embedded in arbitration clauses.