Final answer:
A principal leading a prayer at graduation violates the First Amendment's Establishment Clause as per Supreme Court rulings in cases like Santa Fe Independent School District v. Doe and Lee v. Weisman. School-led or endorsed religious activities are unconstitutional, yet students retain the right to individually exercise religion freely as long as it does not disrupt school activities.
Step-by-step explanation:
A principal who leads a prayer at a graduation violates the First Amendment's Establishment Clause. Landmark cases such as Santa Fe Independent School District v. Doe and Lee v. Weisman have clearly established that any school-led prayer in public schools or school events crosses the boundaries set by the Establishment Clause of the First Amendment, which prohibits the government from making any law "respecting an establishment of religion." While individual students have the right to free exercise of religion, the principle does not extend to school-led or officially endorsed religious activities.
The history of the First Amendment and its application to school prayer has been a complex and sensitive issue. The Supreme Court has deemed school-led prayers unconstitutional because they could be perceived as an endorsement of religion, potentially coercing students into participating in religious activities that may not align with their beliefs, which infringes upon their rights under the Establishment Clause. Conversely, the schools cannot prohibit voluntary, non-disruptive prayer by individuals because that would violate the Free Exercise Clause.