Updated

Supreme Court Justice Antonin Scalia (search) joined law students Monday in a re-enactment of a 100-year-old landmark case — and in less than 30 minutes of debate overturned the verdict.

"There will be no majority opinion. This will be one of those unpublished opinions that will not be citable before the Supreme Court," Scalia joked to laughter after announcing the panel's decision on Lochner v. New York (search).

Monday was the 100th anniversary of the 1905 Lochner decision, in which the high court ruled that a state law limiting bakers' hours violated a bakery owner's liberty and right to due process.

Scalia played the role of Chief Justice Melville Weston Fuller (search), the Chapman University students played the eight associate justices. California Attorney General Bill Lockyer (search) played the part of counsel for New York State.

Robed law students less than half Scalia's age interrupted the Supreme Court justice with questions. But the debate was lighthearted too, as participants made jests on topics ranging from Scalia's Italian heritage to his reputation as a die-hard constitutionalist.

Professor John Eastman, who played the role of Lochner's counsel, argued that the state law had been sponsored by German union members who wanted to prevent competition from harder working Italian immigrant bakers.

To that, Scalia replied "Mama mia!"

The re-enactment was part of a full day of activities for Scalia, who was at Chapman to help the university celebrate the 10th anniversary of its law school.

Chapman has a tradition of inviting distinguished jurists to re-enact important Supreme Court cases on their anniversaries, including Brown v. the Board of Education (search) and Marbury v. Madison. Earlier Monday, Scalia taught a constitutional law class.