General George C. Marshall. He didnt retire from active U.S. Army service until February 1947 and served as Secretary of State until January 1949. In March 1949, he returned to the active list as General of the Army. In September 1950, he became Secretary of Defense. At that time, it was a ten year requirement.
there is no constitutional restriction on the president’s authority to choose his cabinet members. period.
Marshall received a waiver when he was re-appointed Sec Def in 1950, just as Mattis must receive a waiver now.
Great find that invalidates their argument!