By contrast, the debate on a bipartisan climate change bill sponsored by Sens. Joseph I. Lieberman (I-Conn.) and John Warner (R-Va.) offers McCain a chance to stake out a position different from the president's and see if his party will follow. The catch is that many Republicans are uncomfortable with McCain's talk of a cap-and-trade program for reducing carbon emissions.

"John McCain was into climate change before it was cool," [Sen. Lindsey] Graham said. "But that's the one issue where the majority of the conference may go the other way.".

Conservatives hope that McCain will back a more market-based approach rather than the government mandates on carbon emissions that are part of the central Senate proposal.

"We're starting to see a coming together on energy," said Sen. Jim DeMint (R-S.C.). "Hopefully, he can help us find a position between Warner-Lieberman and where we are as conservatives."

But in this internal debate, one can already see a distinct change in the Republican outlook -- conservatives are trying to figure out legislative options on global warming rather than simply playing defense and mocking environmentalists on the topic. The global warming deniers have taken a back seat..

"You've already seen the shift on energy and climate change," said one GOP Senate aide. "You're not going to see tax breaks for oil companies. You'll see us talking more about climate change, where we didn't before."

Of course, we'll all get a chance to see how this plays out next week, when the Senate will debate climate legislation for the first time in three years. The Lieberman-Warner Climate Security Act is set for a procedural vote on June 2, and it will surely be a curious spectacle to behold.

But even more curious are the various GOP senators who are coming out in favor of climate legislation. Warner is, of course, down with his own plan. And Graham, Johnny Isakson of Georgia, and McCain seem supportive if they can lard it up with nuclear subsidies. Bob Corker of Tennessee is talking about introducing his own proposal about how to distribute credits from auction, and has been a vocal critic of the bill as it stands, but he's not against cap-and-trade legislation. George Voinovich of Ohio has put forward his own industry-friendly "plan" to counter the Climate Security Act, with includes a voluntary emissions reduction program, lots of tax incentives for "clean coal" and nuclear power, and a cap-and-trade program only as a fall-back should the voluntary program fail.

And of course there's likely to be input from James Inhofe and pals that will discourage any climate action whatsoever. Fun times on the Hill in the next few weeks.