Current Interpretation

School Administrators have a far greater ability to restrict the speech of their students than the government has to restrict the speech of the general public. Speech and expression can only be prohibited by school administrators if the speech and expression cause a substantial disruption of the school's educational mission. Administrators have the discretion to punish student speech that violates school rules and has the tendency to interfere with legitimate educational and disciplinary objectives. http://law2.umkc.edu/faculty/projects/ftrials/conlaw/studentspeech.htm

The First Amendment has been interpreted by the Court as applying to the entire federal government even though it is only expressly applicable to Congress. The Supreme Court has also recognized that the government may prohibit some speech that may cause a breach of the peace or cause violence. Speeches with advocacy of illegal action, fighting words, commercial speech, and obscenity are not allowed. http://topics.law.cornell.edu/wex/First_amendment

Students have the right to pray individually or in groups or to discuss their religious views with their peers so long as they are not disruptive. School officials may not mandate or organize prayer at graduation, nor may they organize a religious baccalaureate ceremony. Teachers and school administrators, when acting in those capacities, are representatives of the state, and, in those capacities, are themselves prohibited from encouraging or soliciting student religious or anti-religious activity. Students may be taught about religion, but public schools may not teach religion. Students may express their religious beliefs in the form of reports, homework and artwork, and such expressions are constitutionally protected. Student religious clubs in secondary schools must be permitted to meet and to have equal access to campus media to announce their meetings, if a school receives federal funds and permits any student non-curricular club to meet during non-instructional time. http://www.aclu.org/religion-belief/joint-statement-current-law-religion-public-schools

A student has freedom of speech, but if speech is disruptive to the learning enviornment than it must be stopped and the student must be punished.