Answer: As long as they hold good behavior.
Explanation: As long as they play by the rules and do their job correctly and legally, they stay in their position
That a government action violates the Establishment Clause of the United States' constitution if it lacks a secular purpose, has its primary effect as promoting or inhibiting religion, or fosters an excessive entanglement of government with religion.
Used to assess whether a law violates the Establishment Clause. The "Establishment Clause" was intended to prevent any governmental endorsement or support of religion.