Less than 24 hours after the final presidential debate ended with the words “climate change” left unsaid, PBS aired a report that essentially explains the omission.

A closer look at big issues facing the country in the 2012 Election.

“Climate of Doubt,” a “Frontline” documentary presented on Tuesday night, probably allots the biggest single block of national airtime to climate skeptics like Myron Ebell of the Competitive Enterprise Institute, Tim Phillips of Americans for Prosperity and S. Fred Singer than we’ve seen in a long time.

Very little of the production is about the science of climate change. The focus is rather on the ideology and political heft of the skeptics’ movement, and the way it found new life as the economy fell to pieces and the Tea Party arose from the wreckage.

The outlines of the story about sowing doubt about the scientific consensus on climate change have been presented before: the historians Naomi Oreskes and Eric Conway recounted it in their book “Merchants of Doubt,” as did the late climate scientist Stephen Schneider in “Science as a Contact Sport.”

But “Frontline” brings the story up to date. Its examination of how the skeptics have made the issue untouchable is built up brick by brick through interviews with some of the movement’s leading political strategists and their political victims, like the former South Carolina Congressman Bob Inglis, who was defeated in a Republican primary in 2010. The correspondent, John Hockenberry, asks Mr. Ebell about that rout, which many attribute to Mr. Inglis’s speaking out about climate change and the need to arrest it.

Mr. Ebell: Bob Inglis was defeated in a Republican primary, 79 to 21 percent. Now, how many times has an incumbent who isn’t in prison or facing a prison sentence lost his own primary by 79 to 21 percent? This was overwhelming. But, what’s happened is — Mr. Hockenberry: The smile on your face suggests: “Man, we won one!” Mr. Ebell: Of course we won one!

This is one of several exchanges that demonstrate, far better than words on a page, the single-minded pursuit of ideological victory that animates people like Mr. Ebell and Mr. Phillips. Another example is when Mr. Phillips discusses his take-no-prisoners strategy on Republicans who stray from the fold by talking about alternative energy sources.

Mr. Hockenberry: You said “We’ve made great headway.” What it means for candidates in the Republican side is, if you buy into green energy or you play footsie on this issue, you do so at your political peril? Mr. Phillips: You do. Absolutely. And that’s the big change, and it is important. Again, I remember four, five or even three years ago, John, a lot of Republicans, they would play games with this. They’d say: “O.K., oh gosh, I think I need a green energy agenda. But I won’t go all the way and support cap and trade.” They did. They tried to walk down the middle. And that’s wrong. I think it’s philosophically inconsistent, but it’s also politically disadvantageous. And we’ve worked hard to make that so, by the way.

Those who worry about climate change and want to see action taken may squirm with impatience at the limited air time for rebuttal, particularly in the opening segments of the piece. But Mr. Hockenberry’s polite, noncombative style, even when he is confronting Dr. Singer with scientific reports on the question, gives his interviewees the space they need to be themselves. And the result — particularly Dr. Singer’s brisk, confident certainty in the following exchange — is arresting.

Mr. Hockenberry (Reading from a National Academy of Sciences report): “Climate change is occurring and is largely caused by human activities and poses a significant risk for a broad range of human and natural systems.” You say that’s false. Dr. Singer: Yes. Mr. Hockenberry: False. Dr. Singer: False. Mr. Hockenberry: And if most of the climate scientists believe that statement, they are deluded? Dr. Singer (with a smile): Yes. Mr. Hockenberry: And you are seeing something they are not seeing? Dr. Singer: Yes. Mr. Hockenberry: So it’s 97 percent of them and one of you? Dr. Singer: Well, you can put it that way if you like. But I don’t think that’s the way it works. There’s hundreds of us — hundreds, thousands of us. …

Shortly before that exchange, in one of the few segments devoted to the scientific arguments, climate scientists are shown explaining how skeptics can cherry-pick data to argue that there has been no warming in the last decade or so. As Andrew Dessler, a scientist at Texas A & M, put it, “You can, if you want, very carefully select the end points of your time series, the starting month and the ending month, and then maybe you come up with something that shows no warming.”

The one-on-one interviews that dominate the piece are leavened with video clips from hotel meeting rooms where skeptical choirs are being preached to, Tea Party rallies and shots of ocean waves off the North Carolina coast, which is likely to be inundated in a climate-changed world, even though the North Carolina Legislature recently considered banning the acknowledgment of rising sea levels in official deliberations on coastal development. One of the bill’s supporters describes how he relies on a book by Dr. Singer for his information.

In the end, the thinking behind the producers’ decision to go light on science and heavy on ideology in Mr. Hockenberry’s questioning and in the editing of the piece becomes clear. The takeaway from “Climate of Doubt” is that science and its evidence are of secondary importance in the skeptics’ world.

It’s more about fighting what they see as an ideology that wants to subordinate their rights to the authority of the federal government.