... because he doesn’t really understand nuance. Nuance for its own sake it simply mental indecisiveness and abject moral capitulation. It is what Chesterton described as "using mental activity to achieve mental helplessness." Such will often be the case for those who think Intellect is self-contingent and moral in and of itself (IOW, rationalism). For that reason I don’t think John Kerry is all that sharp either. A man who cannot make up his mind might not have one. At any rate, he, like Al Gore, strikes me as decidedly lightweight.
Nuance enables us to figure out a practical way to achieve an ideal goal, or at least begin the movement in that direction. But the ideal comes first. Other than getting his strange self into the big chair, John Kerry has no ideals. The real masters of nuance are people like the Apostle Paul, who for his ideal -the sake of the Gospel- became all things to all men. Another would be Churchill, who, for the purpose of achieving the destruction of Hitler, was very subtle and nuanced ("If Hitler invaded Hell, I should at least make favorable reference to the devil in the HoC").
I would include Bush in that category because he understands that the Moral must trump the Intellectual, or we will ultimately lose both. Nuance must pay its way, like everything else. History will record that Bush made many understandable mistakes in achieving his One Great Thing -continuing the clumsy but forward march of freedom. But Bush, the Man in the Arena, has dared mighty things, and shall know either real victory, or real defeat. In the event of the latter, the final victory will come through at the hands of others.
And the critics will be carping all the way, before they are consigned to a proper oblivion.