Schools Deemed the "marketplace of ideas" as per court ruling according to the 1st amendment

The Court also has recognized that schools function as a "marketplace of ideas" and that the "robust exchange of ideas is a special concern of the First Amendment" (Keyishian v. Board of Regents, 385 U.S. 589, 87 S. Ct. 675, 17 L. Ed. 2d 629 [1967]).
http://law.jrank.org/pages/6348/Education-Law-Student-Speech-First-Amendment.html