The Almanac of American Politics 2020 called Mac “one of Congress’ brainiest and most thoughtful members on national and domestic security issues,” and said that he “has long been at the forefront of national security issues.”  USA Today said Mac has “experience in Washington, a rare long view and a reputation for serious, thoughtful problem-solving.”

Serving on the House Armed Services Committee throughout his time in Congress, Mac was its Chairman from January 2015 to January 2019, the first Texan of either party to hold this position. When House Democrats won the majority in 2018, he became the Ranking Member of the Committee. Mac also served on the House Intelligence Committee for 14 years.

Mac has a proven ability to oversee large organizations with complex missions and dive deeply into specific issues within the context of the broader picture and longer-term trends. Whether engaging with foreign officials or working with those across the political spectrum, he has demonstrated an ability to bring others together for a common purpose.


For each of the six years, he led the Armed Services Committee, Mac has introduced and had signed into law a package of reforms to update and streamline DOD acquisition to get new technologies into the hands of the warfighter faster and to enhance innovation within the Department. He has also been steadfast in his support of the men and women who serve and their families.

Widely respected as an innovator and a strategic thinker, Mac has consistently been on the leading edge of critical national security issues. He led in creating the National Nuclear Security Administration to improve management of the nation’s nuclear weapons complex; establishing the Department of Homeland Security, introducing a bill to do so six months before the attacks of 9/11; preparing the military to defend the nation in new domains of warfare such as space and cyber; and improving oversight of sensitive military and cyber operations.  He also chaired a Cyber Task Force in 2011, bringing together nine committees for a common approach.

Recognized for his nonpartisan approach to national security and for being a persuasive, effective communicator, Mac has written widely on defense matters and appeared on all major television channels providing insight on national security-related issues. 


Born in Clarendon, Texas and raised on the family ranch in Donley County, Mac graduated from Clarendon High School before continuing his education at Texas Tech University.


After obtaining a B.A. in history in 1980, he went on to the University of Texas Law School where he graduated in 1983. For the next several years, he worked in Washington on Capitol Hill and as Deputy Assistant Secretary for Legislative Affairs in the State Department under President Reagan. In 1989, Mac joined his brothers in the cattle business and practiced law in Amarillo until his election to Congress.

Mac's wife, Sally, is also a native Texan. They have two adult children.