Mac is the former Chairman of the House Armed Services Committee. Representing the 13th district of Texas in Congress from 1995 until 2021, he was a leader on national security issues, serving on the Armed Services Committee for 26 years and the Intelligence Committee for 14 years. While Chairman, he pushed reforms to update and streamline DoD acquisition to get new technologies into the hands of the warfighter faster and to enhance innovation within the military. A member of the Council on Foreign Relations, he is a graduate of Texas Tech University and the University of Texas Law School.