Thinking about the Huckabee business more, it seems to me that while he's getting a bum rap over the border issue, it really is the case that he doesn't know what he's talking about when it comes to foreign policy. Not realizing that the Iran NIE had come out is a big deal. The fact that he couldn't provide any explanation of what a Gaffney plus Tom Friedman foreign policy would mean is a big deal. So in a sense maybe it's fair to make a mountain out of a molehill when it comes to a minor geography slip-up.
But I don't really think so. That's the same kind of logic that led the press to conclude it was okay to say Al Gore had lied and said he invented the internet even though he (a) never said that, and (b) what he did say was true. To the press, the important points were (a) the press didn't like Gore, and (b) Gore was a liar. Thus, any anecdote that could possibly be seized on to illustrate the point that Gore was a liar was seized on -- whether or not they were actually lies. It was BS then, and it's BS for it to happen to Huckabee. There's solid evidence out there that he's clueless on foreign policy, so point to the evidence.
After all, consider the opposite. There's also solid evidence that Rudy Giuliani is clueless about foreign policy. But there's no "Giuliani clueless about foreign policy" narrative. Instead, the narrative is about Giuliani's "strength" and "toughness." Similarly, John McCain's long years of interest in foreign affairs are taken as signs of depth and experience, even though what they amount to is long years spent advocating terrible ideas. But Giuliani and McCain haven't made any minor geography errors. Or if they have, they've been ignored. Or something. But on big-picture, real-world stuff that matters, they're all bad and the trivia is still just trivia.