He's not talking about Kyoto as far as I can see, but rather about adopting mandatory greenhouse gas caps and cap-and-trade systems to reduce greenhouse gases. I suppose if he voted against Kyoto that might be something an opponent could bring up to show insincerity or something.

I completely disagree that he's wrong about this in terms of national policy; he's absolutely right and we do need to take action. I'm not even sure it's a bad political move, for a couple of reasons. One, there's an increasingly strong Green Christian movement emerging among evangelicals, focusing on moral stewardship of creation. And two, he needs to give moderates and Democrats every reason to consider his candidacy.