William McClellan "Mac" Thornberry (born July 15, 1958) is an American politician who served as the U.S. representative for Texas's 13th congressional district from 1995 to 2021.

[5] He served as a staffer to two other Texas Republican congressmen, Tom Loeffler and Larry Combest, and as deputy assistant Secretary of State for Legislative Affairs under Ronald Reagan before joining his brothers on the family ranch.

According to the National Journal Congressional Almanac, "In the House, Thornberry has compiled a solidly conservative voting record, though he has a pragmatic streak and is hardly the most ideological Republican in the Texas delegation.

'"[17] From January 1995 to July 2017, Thornberry missed 140 of 15,276 roll call votes, or 0.9%, fewer than the median of 2.2% among the lifetime records of representatives currently serving.

[18] Thornberry was critical of President Barack Obama's 2010 arms control deal with Russia for precluding the use of nuclear weapons against non-nuclear nations.

He served on a bipartisan commission in 2007 that drew up recommendations for winning the war in Iraq with both lethal and non-lethal approaches, such as diplomacy and foreign aid.

[1] In 2010 Thornberry sponsored a bill to expand access to state veterans' homes to parents whose children died while serving in the military.

In January 2011 he introduced a bill to help states set up special health care courts staffed by judges with expertise in the subject.

The judges would serve as an alternative to juries that Republicans say are inclined to award unnecessarily large damage amounts in malpractice cases.

[19] Thornberry pressed the House to pass a farm bill every five years in order to give farmers and ranchers more stability.

In 2016, he set acquisition reform as a key feature of the annual defense spending bill, including steps such as more experimentation with technology, encouragement of competition and clarification of intellectual property rights of Pentagon contractors.

"[27] In 2011, House Speaker John Boehner selected Thornberry to lead an initiative on cybersecurity to combat the growing national security and economic threat.

We still have larger issues to grapple with, such as the role of the Department of Homeland Security and whether some industries will require a regulatory nudge to improve their network standards.

1186, the Synthetic Abuse and Labeling Toxic Substances (SALTS) Act, which would make it easier for law enforcement officials to take action against synthetic drug manufacturers, distributors, and sellers by closing a loophole that makes it difficult to prosecute them if they label packages as "not intended for human consumption.

"[32] Thornberry defeated Democratic Congressman Bill Sarpalius in the 1994 general election, a heavily Republican year nationwide.