She's missing the point, of course. To the extent that a president is intelligent and well-educated, that's all to the good. Voters aren't concerned that someone is "too smart" or "too nuanced." Rather, they worry (with good reason, judging from some of Barack's recent remarks) that with the "intellect" comes a lack of practical horse sense and life experience or, worse yet, a certain elitist contempt for them and their values (George Will lays it out brilliantly here).
One final comment: How is it that so many in the press or entertainment world have no objection to electing a president "who is embarrassingly superior to me" (as Daum quotes Jon Stewart) when it's a lefty like Barack, but when it's Republican Mitt Romney, the cry goes up that he's just "too perfect"?