Josh Marshall considers the possible impact of a Libertarian run by Bob Barr. He mentions "the South," but in the next sentence that becomes "Deep South," and although he goes back to "the South" in the next graf, he doesn't seem to have North Carolina in mind.
But North Carolina isn't Mississippi, and I'm not sure Marshall's calculus holds up here. I'd point to the turning of Freedom Fries Jones away from the war, and his subsequent primary victory, as evidence that North Carolina Republicans don't have some sort of blind faith in Bush's Iraq policy.
Given the blue tide we saw in NC last week, the prospect of a relatively strong Libertarian in the race can't be comforting to McCain, who got less than 75% of the primary vote here, while Ron Paul and No Preference combined for more than 10%.
If the McCain-Obama gap tightens, Barr could make things interesting in NC.