He is one interesting character. Barr was defeated after the Democratic-controlled Georgia Legislature redistricted his seat in 2002 to have him essentially run for the new district against another Republican incumbent. The libertarians came out with an ad criticizing Barr for his tough stand on medical marijuana (he was the anti-drug coordinator for the Dept of Justice), and he was defeated 2-1. He voted for the Patriot Act, but only after his "sunset clauses" were added as amendments. He regrets his Patriot Act vote and now lobbies for state choice on medical marijuana. Barr is also a supporter of the Fair Tax and repealing the 16th Amendment[33], which gives the US Congress the right to levy an income tax.
Barr joined the Libertarian Party in 2006 and now serves on it's National Committee. The perfect Libertarian candidate.

I can't think of too many pro-Clinton Democrats that would vote for Bob Barr because of his part in the impeachment of WJC. Perhaps some of those Obama leaning Independents might find his message more appealing. I'd imagine more than a few Republicans might be intrigued. 3rd party candidates generally don't affect elections much, except for that Florida in 2000 thing and that Ross Perot run in 1992...

I don't know what affect he might have on this race.

I could actually see Obama losing votes to Barr as much as anyone.

seeking the Libertarian nod?