I went another way in the PP post, but another way to think about this is that, yes, favorability numbers should be thought of as a function of political skills and not some innate likability. To put it another way: likeability is generally not separate from other skills a politician might have. Oh, sure; there may be someone somewhere who would have terrific bargaining abilities and overall political sense but just repel so many voters that he or she would be unable to be elected. But that certainly can’t be the case for presidential nominees, who cannot make it that far without making themselves at least somewhat appealing to voters.
And the key there is “making themselves.” Political images aren’t something inherent in politicians; they are products created by candidacies and by the interaction of those politicians with the rest of the political world. Remember: everything you see, from one-on-one interviews to convention speeches to, yes, debate performances, is almost always thoroughly rehearsed and prepared. Nor are those performances received in isolation. Barack Obama was more charming – perceived as more charming – in 2008 than in 2010, not because he changed but because the political context changed. One reason why nominees look great at their conventions, as Romney will undoubtedly look great tomorrow night, is because they are by definition winners, and winners always look better than losers.
In that same vein, I have no problem with anyone who wants to watch the candidates -- or their spouses -- to get some idea of the persona that they'll be displaying in public should they win. But don't be fooled: what they show shouldn't in any sense be thought of as who they "really" are. Nor should you trust reporters to get at it. Every politician, and certainly every one of them who reaches that level, learns to put on a public face for the cameras -- and, yes, for those quieter interviews and "candid" moments, as well. Which is fine; of course they do that. It's part of the job. Just don't mistake it for something other than what it is.
(And it's not just what they're trying to do. We have lots and lots of examples of times when reporters apparently just got it wrong, perhaps because they tend to fall pretty easily for politicians -- or celebrities, or ballplayers -- who put real effort into working them. Kirby Puckett, anyone?).