The U.S. Supreme Court has now heard oral arguments in the three cases before it in which corporate defendants are seeking broad new rulings further limiting the use of class actions in federal courts. A narrower case trying to block a consumer class action, DirecTV v. Imburgia, was decided on Dec. 12, with the court re-emphasizing that class action bans in mandatory arbitration clauses will be enforced.

No one knows how the court is going to rule in these cases. The oral arguments suggest, however, that, for three reasons, the court may be unlikely to issue the far-reaching decisions the corporations are seeking — and class action practitioners fear.