Student's Rights
"It can hardly be argued that either students or teachers shed their constitutional rights to freedom of speech or expression at the schoolhouse gate" - The Supreme Court (1969)
The United States constitution affords citizens several rights in order to defend their liberty to self expression. Although students are by nature of the school environment, limited in the freedoms granted under law, they still receive the protections of freedom of speech.
Free Speech & Assembly
Students are protected under the 1st amendment to express free speech but its important to first understand what that means in the context of schools. The supreme court asserted in the case "Tinker v Des Moines" that students maintain the freedom of speech, so long as the form in which that speech is expressed is not disruptive. However, later the supreme court clarified in the case "Bethel v Fraser" that school administrations do not violate the freedom of speech protections of the 1st amendment by censoring "vulgar" speech.
This means that while you can't stand up in the middle of class and shout of expletives about how you hate the math, you are fully protected in hosting a protest during your lunch period so long as "swearing" is kept to a minimum
Student Club Protections
Equal Access Act
In 1984, the United States congress passed the "Equal Access Act" of 1984 which created protections against discrimination on the basis of religious, philosophical, or political speech conducted by Student organizations in High schools. The act requires clubs seeking protection to be student led and initiated, completely voluntary, and must receive no government funding or sponsorship (as well as the obvious requirement that the organization does not commit illegal acts). This applies to all schools who permit at least a single "extracurricular" student club, requiring that should a school permit a single extracurricular club, it must permit all extracurricular clubs.
Board of Westside Community v Mergens
In 1990, the Supreme Court reviewed the constitutional validity of the Equal Access Act when they heard the case of Board of Westside Community Schools v Bridget Mergens. The Court affirmed the doctrine established by the EAA and established the precedent for constitutional student group protections providing that the organization follows the guidelines set out in the EAA.