Nick Gillespie notes he's "simply tired of [McCain's] genuinely awe-inspiring war bio." I can appreciate that sentiment. Those of us who are political junkies have heard the McCain POW story many times now. (And there are many libertarians who claim not to be political junkies, but nonetheless are.) But an enormous part of the population is only getting interested in the presidential race right about now, and some of this stuff about Hanoi might be news to them.
More substantively, Gillespie writes that McCain "really leaves me cold with the emphasis on service and communitarian-type ideals." To a degree, I share that sentiment too. I'm not as libertarian as the people I used to collaborate with at Reason, but as a McCain supporter I would like to hear more from the candidate about how a sense of national and community solidarity is needed in a free, individualistic society, precisely to protect that freedom and individualism.
Lest anyone say that this is not McCain's view, I refer them to his statement after the Kelo Supreme Court case that "individual liberty and the free market are paramount."
UPDATE 2:53PM: And see post above.