Mike Gravel came in fourth in delegate votes for the Libertarian Party presidential nomination in 2008, behind Bob Barr, Mary Ruwart and Wayne Root. Before that, he ran in Democratic Party primaries for President that same year, and served as a Democratic US Senator from Alaska from 1969 to 1981. Accoring to wikipedia,
As Senator, Gravel became nationally known for his forceful but unsuccessful attempts to end the draft during the Vietnam War and for having put the Pentagon Papers into the public record in 1971 despite risk to himself. He conducted an unusual campaign for the Democratic nomination for Vice President of the United States in 1972, and then played a crucial role in getting Congressional approval for the Trans-Alaska pipeline in 1973.
More recently, he has been making videos at Barely Political. Here are the recent ones: