School officials denied student Pete Palmer the right to wear a shirt supporting John Edwards's presidential campaign at his Dallas-area high school. They cited the district's dress code, which prohibited messages on student clothing except for those that supported school activities or district-approved organizations, clubs or teams. The Fifth Circuit agreed with the school district that this was a reasonable "time, place and manner" speech restriction. Applying the test from United States v. O'Brien, the court found that the dress code was content- and viewpoint-neutral, and served an important governmental purpose. Palmer now seeks Supreme Court review, citing seemingly contradictory precedents from the Second and Third Circuits and arguing that the regulation here flies in the face of the protection afforded to student speech by the famous case of Tinker v. Des Moines Independent Community School District. Cato, joined by the Institute for Justice, the Becket Fund for Religious Liberty, the Christian Legal Society, and the National Association of Evangelicals, filed an amicus brief supporting Palmer's petition and urging the continued use of Tinker. We argue that the Court should clarify its jurisprudence in this area to stop schools from applying broad restrictions in an attempt to avoid controversy and debate—and thereby threaten the very political and religious speech at the First Amendment's core. To prevent the chilling of student speech, the Court should solidify Tinker's central tenet, reaffirming that so long as speech doesn't "materially and substantially disrupt" the educational process, students do not "shed their constitutional rights to freedom of speech or expression at the schoolhouse gate."