The United States Court of Appeals for the Third Circuit has held that teaching a course in the Science of Creative Intelligence Transcendental Meditation in public high schools is an establishment of religion prohibited by the first amendment.
Malnak v. Yogi, 592 F.2d 197 (3d Cir. 1979).
Jennifer F. Rabold,
Constitutional Law - First Amendment - Establishment of Religion,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol18/iss2/8