Paulus, I think Buchanan is suggesting what Peter Schiff was, that of the two major party candidates, Romney is the more likely to fall back on founding principles when his "corporatist" dealings bring about the nation's collapse. I detect a high degree of doubt in his statement that begins "If a President Romney held to that rule..." I think he's just trying to put up the best hope.
All that being said, I'm voting for Johnson, and I would hope anyone who's researched him at all would agree that he's the best candidate. Certainly, if you're not in a swing state, I can't imagine why you would NOT vote for him. In a swing state, I can imagine why you wouldn't, but I still think you'd be wrong not to.