Why is Obama allowed to quote the bible?

Students in public schools do not have free speech. That was decided by the Supreme Court a long time ago. A valedictorian at a private Christian school is allowed to say whatever he/she wants about God, but it was decided that to force a public school student to hear about any religion is a violation of his/her rights. One might ask about students' freedom of religion. The Supreme Court would answer that they are not removing students' right to practice religion. They are only disallowing them from forcing others to see or hear it. There is no command in the Bible that forces a follower to pray in public, or talk about God during school hours. Do I agree with this. No. A school should not force any student to observe any religious practice, but I believe that a students' free speech should not be infringed. The problem, however, is that it was decided that offensive language could be prohibited at a public school. Most people would agree with that. But apparently atheists find any mention of God offensive, so it has gotten sticky. What would happen if a Muslim filed suit because a school mentioned pork, and he/she felt offended? Who knows. Maybe we'll find out some day.