I still don't have a complete line on him, but I think he's something of a libertarian. We're not going to agree with most of his positions, but in this case there's no reason to be suspicious.
On edit: found a relevant article.
http://reason.com/0312/cr.jw.bob.shtmlBob Barr, Civil Libertarian
The right wing of the ACLU
Interviewed by Jesse Walker
After entering the House of Representatives in 1995, Georgia Republican Bob Barr acquired a reputation as one of the most conservative members of Congress. It was Barr who in 1996 wrote the Defense of Marriage Act, which said states didn’t have to recognize gay marriages performed in other states; it was Barr who protested when he learned the military allowed soldiers to practice Wicca. A former federal prosecutor, a firm social conservative, and a strong supporter of the War on Drugs, Barr doesn’t fit most people’s image of a civil libertarian.
But in his eight years in Congress (he failed to win re-election in 2002), Barr was one of Washington’s loudest critics of the federal government’s abuses of power, taking the lead in investigating the raid on Waco and in opposing Bill Clinton’s efforts to undermine due process in terrorism cases. Since leaving Congress, Barr has taken an advisory post with the American Civil Liberties Union (ACLU) and started writing a column for Atlanta’s alternative weekly Creative Loafing -- neither ordinarily a haven for Republicans. While many on the right have fallen behind the Bush administration even as it betrays their purported principles, Barr represents another set of conservatives' growing discomfort with the administration’s erosion of individual liberty.