How Chief Justice Roberts handles the case could have outsized importance. Compared to some of the other five members of the court’s conservative bloc, he is broadly seen as more likely to be concerned about the institutional impact on the court if it makes a wrenching and politically contentious change in the law. He also has the power to assign himself to write the opinion if he votes with the majority.

Known for crafting narrow and incremental decisions, Chief Justice Roberts distinguished on Wednesday between an outright ban on abortion and a ban on the procedure that was stricter than the current standard. At one point, he remarked that he thought moving the cutoff line to 15 weeks — nine weeks earlier than where it is now — was “not a dramatic departure from viability.”

He also told the solicitor general, Elizabeth Prelogar, who was supporting the challengers to the law, that the arguments she had made regarding problems that would result from overruling Roe “sounded to me like being based on a total prohibition.” He said he wondered how strong those arguments “would be if there isn’t a total prohibition.”