The justices on Monday ordered a federal appeals court to restudy the case in light of their decision last June to bar student-led prayers at public high school football games. The justices said such prayers violated the constitutionally required separation of government and religion.
In 1992, the justices prohibited clergy-led prayers at public school graduations.
Invocations and benedictions were allowed at Duval County, Fla., public school graduations before the 1992 ruling.
In 1993, school officials adopted a new policy letting high school seniors decide whether to choose a fellow student to give a "brief opening and/or closing message" at graduation. The student would decide the message's content with no review by school officials.
A group of students and their parents sued in 1998, saying the policy amounted to a government establishment of religion, barred by the Constitution's First Amendment.
Under the policy, students at some schools have elected a class chaplain to lead invocations and benedictions, or to give messages designated as "reflections" or "inspiration" and "farewell."
A federal judge upheld the policy. A three-judge panel of the 11th U.S. Circuit Court of Appeals reversed, but the full appeals court ruled for the school district last March.
The court cited the "total absence of state involvement" in deciding whether there would be a graduation message, who would give it, and what would be said. The Duval County schools' policy is neutral toward religion because "the venue is equally available for religious or secular expression," the court said.
In the appeal acted on Monday, the students' lawyers said the policy's main purpose was to promote religion and that its supposed secular purpose was a "sham."
The policy "results in state coercion of student participation in religious exercises" because students are required to attend their graduations, the appeal said.
The school board's lawyers said the policy "neither establishes nor prohibits religious speech. It merely permits graduating senior classes to decide whether or not to include an unrestricted message as part of their ceremonies."
Any student messages given under the policy are "purely private speech," the board's lawyers said.
The case is Adler v. Duval County School Board, 99-1870.