Does Bob Barr hurt Obama’s chances?

This entry by John Scalzi on Bob Barr’s announcement that he is officially running for the Libertarian Party nomination for president is one of the better takes I’ve read on the prospects of Barr’s candidacy.

But let’s be real, here: the question [sic] not really whether I put Barr ahead of McCain in my voting queue, since I had no intention of voting for McCain in the first place. The question is whether some folks who might otherwise vote for McCain will do so, and whether there will be enough of them to constitute a genuine drag on McCain in the election. …

That’s certainly the case to an extent, but I wonder why no one seems to be talking about the other possibility, that Obama’s vote totals will also fall. I know I’ve encountered libertarians who are considering voting for Obama because they’d never vote for McCain. If they now vote for Barr if he wins the LP nomination, how much will that matter to Obama’s chances? I don’t have the answer, but it’s a question at least as worthy when considering the possibility that McCain is auditioning for a third Bush term. I know of few libertarians who would consider that for a moment, so Barr just isn’t stealing votes from there.

The liberaltarian meme is mostly policy crap designed to push libertarians to embrace a progressive agenda rather than a (classical) liberal approach to government. But it has adherents. How will they vote?

For what it’s worth, the quick link Mr. Scalzi provides to Barr’s policy positions reminds me why I’m very skeptical of Barr. The anti-immigration stance is troubling, at best, but throwing his support behind the Fair Tax as a “well-researched alternative” leaves me cold. Well-researched, maybe, but accurately marketed? Not so much.