It was a weighty middle of the week for Chief Justice Roberts. On Wednesday, he issued an opinion upholding lethal injection as a method for executing prisoners. The same day, he heard arguments on whether the death sentence can be imposed for crimes other than murder.

But his workweek lightened yesterday when he entered the jurisdiction of Columbia Law School and heard arguments in Nafziger v. Kaergard, a fictitious case of no consequence that is unlikely to be discussed in future years, other than by the four Columbia law students who argued it for a moot court competition before the chief justice.

Even when presiding over a classroom, Justice Roberts sounded very much himself. From a makeshift bench in a lecture hall at Columbia, he cautioned against judicial incursions on legislative judgments and asked questions in the same vein that he pursues at One First Street in Washington, D.C.

The chief justice shared the bench with three circuit court judges: Diana Gribbon Motz, Diane Wood, and Michael McConnell. It was Judge McConnell of the 10th Circuit who appeared to take most to the case, which weighed whether women in Illinois can bring a class-action suit against the state for denying them quality medical care while they were enrolled in a state-administered health insurance plan funded by Medicaid.

It was not the sort of headliner that would ever draw protesters or television cameras to the steps of the U.S. Supreme Court. But it was familiar material for Justice Roberts, who had argued two of the Supreme Court cases cited as precedents by the soon-to-be-attorneys arguing before him. One of those cases, Wilder v. Virginia Hospital Association, Justice Roberts lost, while the other, Gonzaga University v. Doe, he won.

One of the lesser-known perks of being chief justice of the United States was on display yesterday: People laughed heartily at each amusing remark he uttered. During the arguments, Justice Roberts drew laughter from the audience on at least four occasions as he spoke with deprecation about his knowledge of economics and pointed out the tautological shortcomings of an argument. His fellow judges failed to elicit a single chuckle from the audience.

The four judges voted Christopher Hogan, of the class of 2008, the winner of the Harlan Fiske Stone Moot Court Competition.