As I watched last night's debate, it struck me, not for the first time, that Mitt Romney is really, really articulate. He's not particularly eloquent -- his words aren't going to move you to tears -- but he speaks in full sentences, at times even in full paragraphs. He rarely stumbles, or gets halfway into a sentence, backs out, and then starts again, like most of us do when speaking. There are times when he pauses for just a few milliseconds searching for the right word, but he always seems to find it, and it's usually a pretty good one.
Newt Gingrich, on the other hand, is both articulate and fairly eloquent -- his sentences are more likely to have a poetic sweep, although he does rely on a couple of rhetorical crutches that get old once you've heard them a few hundred times (every change must be "fundamental," things he likes are "profound," and things he doesn't like are "corrupt"). Being articulate is part natural talent, but mostly practice. In Romney's case, he probably delivered a thousand PowerPoint presentations before he ever ran for office; in Gingrich's case, he's spent the last few decades bloviating to rapt audiences on an almost daily basis.
In order to be articulate, you also need to be immersed in the subject matter at hand to the point where your statements come easily. Fred Barnes once accidentally uttered the pundit's motto when he said, "I can speak to almost anything with a lot of authority." As Eric Alterman observed, "he was right, at least to the degree that he was really saying, 'I can speak to almost anything without anyone pointing out how full of shit I usually am.'" That's partly about the mannerisms of certainty that Barnes had learned, but also about the fact that because being a pundit is his job, he keeps up with whatever issues are currently being debated and felt sure that he could address any topic that came up on The McLaughlin Group, at least well enough to rattle off a few sentences.
But Rick Perry is neither articulate nor eloquent, and as Jonathan Chait says, he sounds fine when he's talking about Texas, but stumbles whenever he has to address national issues. "The likely explanation for Perry's travails is that he simply never paid much attention to national politics before." At the very least, he hasn't been immersed in the issues in a way that would allow him to talk for 60 seconds with a lot of authority. Unfortunately for him, that makes him look a lot less presidential than the other contenders, all of whom are better talkers than he is. Since pretty much all you do as a presidential candidate is talk (with the occasional wolfing of a corn dog for the cameras thrown in), this is very, very bad for Perry. Debate coaching might not hurt, but it won't solve the basic problem. It takes years to become truly articulate and months at least to get up to speed on all the issues you might be asked about if you're running for president. He just doesn't have that kind of time.