I think in good times, people vote personality over anything—and these are good times. Think about it. When things are going well, what are you gravitating toward? You want the guy who can crack a good joke, tell a good story, slap you on the back and have a good laugh. You don’t look at deeper issues, one has to hit you in the face and matter for long enough to make you remember at the polls.
I agree with good times coinciding with ‘likability’ having a greater influence. But these are serious times (we’re at war) and we cannot have a candidate so naive on foreign policy (Gitmo, Bhutto, NIE, etc. - Secretary Rice took him to task on all of this). The terrorists are watching.