The author reports on how U.S. Supreme Court Justice Clarence Thomas' opinions in youths'-rights cases reflect his "originalist" thinking. Justice Thomas, 63, marks two decades on the court Oct. 23, and a hallmark of his tenure is his willingness to carve out a solitary stance on certain issues. Particularly in cases involving schools and the rights of children, he has issued sharp dissents from some of the rulings of his liberal colleagues, and concurrences that go further to the right than even some of his fellow conservatives. Justice Thomas is not always isolated in his views. In the eyes of some legal observers, he has gained an influential place on the largely conservative court of Chief Justice John G. Roberts Jr. An August article in "The New Yorker" said that "in several of the most important areas of constitutional law, Thomas has emerged as an intellectual leader" of the court, specifically in the areas of gun rights and in the free speech of corporations.