Repeat it often enough, people will believe it. The Senate said it wouldn't ratify Kyoto back in 1998, and Clinton never submitted it. Bush also simply refused to submit it. The reason for everyone not going along is that it gives a free pass to "developing" nations like China (which will, as a Kyoto country, surpass us in CO2 in 2010).
IOW, to put this on Bush's head is a flat-out lie meant to make it look like he doesn't care about the environment.
They never mention the Senate vote, do they?
Another reason for Bush was the idea it was junk science. The Bush admin has spent a lot on data collection and other research because all they really had was a hypothesis.