The national Libertarian Party picked former Republican Rep. Bob Barr to be its presidential candidate at their national convention in Denver this weekend.

Taking six rounds, the former Georgia Congressman Bob Barr beat research scientist Mary Ruwart with a 324-276 vote. Barr had been a member of the GOP, but left the Republicans in 2006 over claims of bloated spending by the Bush administration.

Barr was one of the more conservative Republicans in Congress during his three terms. He was best known for his efforts for a complete federal prohibition of medical marijuana and anti-drug legislation which stemmed from his previous experience as Anti-Drug Coordinator for the Department of Justice.

Former two-term Alaska senator Mike Gravel also ran for the presidential nomination of the Libertarian Party. He announced that he was leaving politics this weekend when his efforts to win the Libertarian Party’s nomination fell short.

Gravel left the Democratic Party in 2007 after as a presidential candidate, Gravel was excluded from some Democratic presidential debates because he failed to meet fundraising or polling thresholds. As a Senator, Gravel became nationally known for unsuccessful attempts to end the draft during the Vietnam War and for having put the Pentagon Papers into the public record in 1971. He left the political arena after his unsuccessful run for a third Senate term and his run for the president in 2007.