Is there a right way or a wrong way for an advocate to tell a U.S. Supreme Court justice that he or she is wrong during oral arguments?

Arnold & Porter Kaye Scholer's Lisa Blatt drew raised eyebrows last week when she told Justice Elena Kagan she was "fundamentally wrong in several respects." When Kagan pressed her—"fundamentally wrong?" she asked—Blatt responded: "Well, it's factually wrong."

"Factually and fundamentally?" Kagan responded, drawing laughter. Kagan took the correction with her trademark good humor and perhaps also because she is familiar with Blatt's own forceful style as a veteran advocate.