What you Can Say
Most speech is protected under the First Amendment. This is one of the basic constitutional rights guaranteed to Americans in the First Amendment of the Bill of Rights. The Founding Fathers believed that a free society must allow its citizens to freely express themselves without government interference.
The values associated with free speech include:
~The Discovery of Truth ~ Facilitating Participation by Citizens in Political DecisionMaking ~ Creating a More Adaptable and Stable Community ~ Checking Abuse of Governmental Power ~ Creating a More Robust and Interesting Community
The school district (or any governmental agency) cannot prohibit a speaker because of the viewpoint that person wishes to expresses or because they do not want that particular person to speak.