Forbes formerly served as Chairman of the Seapower and Projection Forces Subcommittee of the House Armed Services Committee.

On February 8, 2016, he announced that he would run for election to Virginia's 2nd Congressional District in November 2016 after a court-ordered redistricting saw the 4th absorb most of the majority-black areas around Richmond.

Forbes stated that his seniority gave him a chance to become the first Virginian to chair the House Armed Services Committee.

[12] On June 14, 2016, Forbes was defeated in the Republican primary by Scott Taylor by a margin of 52.5% to 40.6%, with a third candidate, C. Pat Cardwell IV, receiving 6.8% of the vote.

[14] The largest donors to Forbes over his Congressional career have been defense contractors serving the U.S. Navy for aviation and ship construction, including Northrop Grumman, BAE Systems, Leidos and Huntington Ingalls.

[15] After leaving Congress in 2017, Forbes joined the Government Law & Policy Practice’s Federal team at Greenberg Traurig as a senior director.

[17][18] Forbes was formerly Chairman of the House Armed Services Committee's Seapower and Projection Forces subcommittee.

[22] Forbes spoke a panel discussion at Harvard University in the April 2012 on U.S. strategy to China's world power emergence.

[23] Forbes has voiced concern for Chinese military ambition, cyber threats, contaminated exports, and human rights violations.

On June 26, 2009, the bill was offered as an amendment in the nature of a substitute for the Waxman/Markey-sponsored American Clean Energy and Security Act.

** Sisisky died on March 29, 2001; Forbes won the 2001 special election to fill out the remainder of his term.