Every FBI, CIA, member of Congress / Senate…swore this oath…

5 U.S. Code § 3331 - Oath of office

An individual, except the President, elected or appointed to an office of honor or profit in the civil service or uniformed services, shall take the following oath: “I, AB, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter. So help me God.”

https://www.law.cornell.edu/uscode/text/5/3331