Last week, the White House issued a new and alarming edition of its national report on climate change. How did leading Republicans respond?
Sen. Mitch McConnell, R-Ky., the GOP's leader in the Senate, scoffed at President Barack Obama for "talking about the weather," dismissing the issue as a hobbyhorse of "liberal elites ... who leave a giant carbon footprint and then lecture everybody else about low-flow toilets."
After pointing out that the president is "not a meteorologist," Sen. Marco Rubio, R-Fla., argued that Obama's proposals to regulate carbon emissions "would have a devastating effect on our economy" without solving the problem.
And Sen. John Thune, R-S.D., said the central issue wasn't climate change but cost-benefit analysis. Asked whether he thought global warming had been caused by human activity, Thune said: "I'm not denying that. I'm simply saying that the debate ought to be: What are we going to do about it, and at what cost?"
Perhaps this counts as progress. They weren't calling climate change a hoax, as many conservatives once did (and some still do). They're not even challenging the scientific consensus that human activity has contributed to the warming of the Earth (although some still contest that finding too).
Why the shift?
Polls have found that most Americans are worried about global warming, except for one group -- tea party conservatives. A Pew Research Poll conducted last year found that only 25 percent of tea party adherents believe climate change is real, against 61 percent of non-tea party Republicans (and 84 percent of Democrats).
That puts the GOP in a bind, caught between its most zealous conservative supporters and the broader majorities it'll need to win elections.
More worrisome for the GOP, younger voters are even more convinced that climate change is a big problem -- and they're going to be around longer than their grandparents.
And, remarkably, almost two-thirds of Americans, including about half of Republicans, favor stricter limits on emissions from power plants, the centerpiece of Obama's regulatory agenda.
"In the short term, it's politically smart for Republican politicians to express doubts about climate change because that responds to what their base wants," said Sherwood Boehlert, a moderate former GOP congressman from upstate New York who chaired the House Science and Technology Committee for six years until 2007. "But public opinion is moving forward, and that won't be good for the deniers."
In the not-too-distant past, the Republican Party's platform actually listed global warming as a national problem and cited "human activity" among its causes. But that was 2008, when Sen. John McCain, R-Ariz., was the nominee; even Sarah Palin, his running mate, agreed. "It's real," she said then. "We need to do something about it."
But that was before the tea party insurgency of 2010, and before Democratic proposals for cap-and-trade legislation made climate change a forbidden zone for most Republican politicians -- including McCain, who abandoned his earlier positions and fell in line. Last year, when Sen. James Inhofe, R-Okla., proposed an amendment to ban any new federal regulation of greenhouse gases, only one Republican voted against it: Sen. Susan Collins, R-Maine.
Now only a few defiant Republican moderates still argue for policies to counter climate change, including former Gov. Jon Huntsman of Utah and former Sen. Olympia Snowe of Maine. Except for Collins, they're all out of office.
Some current GOP members of Congress still deny that the problem exists, including Rep. Dana Rohrabacher, R-Calif., who has called global warming "a total fraud" designed by "liberals who ... want to create global government."
Others agree that climate change is real but say they aren't certain that it's man-made -- and, as a result, they feel no need to fix it.
"People like me who support hydrocarbon development don't deny that climate is changing," Rep. Joe Barton, R-Texas, said last year. "If you're a believer in the Bible, one would have to say the great flood is an example of climate change, and that certainly isn't because mankind had overdeveloped hydrocarbon energy."
That argument has always struck me as odd: If climate change isn't man-made, does that mean there's no reason to try to counter its effects? Noah's flood wasn't man-made, but he still spent the money (or at least the timber) to build an ark.
But increasingly, the most popular argument among leading Republicans in Congress is a mix of all of the above -- maybe it's a problem, maybe it isn't -- plus a new talking point designed for tough economic times: Whatever the problem, it looks too expensive to fix.
"There has to be a cost-benefit analysis," Rubio said last year. "The benefit, I think, is difficult to justify. ... Is there anything government can do about it that will actually make a difference?"
It sounds, for a moment, as if Rubio is criticizing Obama for being too timid in his regulatory proposals. But it's really just another argument for doing nothing.
That position would carry more weight if Rubio and other Republicans had actually done the cost-benefit analysis they ask for, one that includes the costs of flooding in Miami and droughts in the Southwest as well as the price of regulating coal-burning power plants. But they haven't.
To borrow a word from a different public debate, the GOP appears to be evolving, but only in its rhetoric, not its policies. But evolution is a slow process, and if the environment changes as quickly as the scientists expect, some political species could soon become endangered.
Contact Doyle McManus at firstname.lastname@example.org