Mary Ruwart

Former U.S. Rep. Bob Barr won the Libertarian nomination for president Sunday afternoon at the Denver Sheraton.

Barr won on the sixth ballot over longtime Libertarian activist Mary Ruwart.

Libertarian National Convention delegates now have to select a vice-presidential candidate.

"This will be a historic and positive campaign that will succeed," Barr said in his victory speech. "This is a campaign that will win."

Seven Libertarians debate in Denver: From left: former U.S. Rep. Bob Barr; former U.S. Sen. Mike Gravel; Libertarian activists George Phillies, Michael Jingozian, Mary Ruwart, Steve Kubby, and Wayne Allyn Root.

Seven candidates for the Libertarian presidential nomination squared off at a Denver debate Saturday evening, the day before Libertarian National Convention delegates vote on what’s considered to be a wide-open race for the nomination.

Although the seven candidates come from a range of political backgrounds, all largely agreed Saturday  on a variety of issues ranging from opposing the Iraq War and government-run health care to supporting gun rights and ending the war on drugs.

The seven debaters were former U.S. Rep. Bob Barr (R-Ga.); former U.S. Senator Mike Gravel (D-Alaska); Las Vegas oddsmaker Wayne Allyn Root; Libertarian activists George Phillies of Massachusetts and Michael Jingozian of Oregon; and former California gubernatorial candidate Steve Kubby.

The moderator was Fox News contributor James Pinkerton.