Science and democracy are supposed to go together like Mom and apple pie. But in the American political arena, they aren't naturally compatible: To show people Science, you have to tell them the truth, about what you know and how you know it. To get people to take political action, though, you have to lie.

You can call it "honing the message" and "communicating effectively" and "not letting the other side define the story." Whatever. If you tell me your energy policy will create secure and prosperous jobs, you're lying. Not about the policy, but about your ability to predict the future. If you say science has proven that you're right, you're lying. Not about the issue at hand, but about the nature of science.

Yet who is going to attend a rally under a banner that says "We Think This Policy Is Worth Trying For Many Reasons" ? Mass email campaigns, noisy rallies, voter-turnout drives and the like all demand unwavering certainty. But doing science demands a certain wavering—a willingness to reconsider and a clear-eyed sense of the limits of your knowledge. As James Hansen put it last spring, when I heard him comment on the effective communications of Al Gore. Gore, he told us, "said in 'An Inconvenient Truth' that there are 930 papers that agreed on human-made climate change and zero that disagreed with it. Well, that's just not normal for science. Scientists are always attracted to the possibility that everybody else might be wrong, so they love to try to come up with ideas for how maybe the consensus is wrong. So it's not 930 to zero."

Unlike religious, commercial or purely ideological lobbying groups, advocates for "science-based policies" have to wrestle with this contradiction. How much simplification is too much? When does an exaggeration become an outright distortion? That's the balance the President has to strike in running an administration which, he said, will "make scientific decisions based on facts, not ideology." He had pledged to be true to science, by saying he'll follow it where it leads. But you can't follow science everywhere and be a politician, because science might lead you across the ideological lines on which politics depends. Or, as often happens, it might lead you back and forth across those lines.

That's not to knock the President, who, in the community of professional manipulators in which he works, is often criticized for being too open-minded himself. No matter who is President, a political system that works by getting people fired up can't address questions that require them to calm down.

Yet the professional "firer-uppers" have so perfected their art that each science-related public-policy question, from sustainable energy to population demographics, has been turned into one more "urgent appeal"—one more petition, pledge or slogan; one more email in which some politician addresses me as "Dear David"; one more application of political techniques that turns the world's real difficulties into an absurd Good-versus-Evil cartoon.

This seems to have triggered two responses in the U.S. electorate this year. One is a desire to stay outside the system of mass email campaigns, robo-calls, "save the nation" meet-ups and the like. That helps troglodyte pols who seem too rough, ignorant or tongue-tied to do what the professionals advise. Cranks and morons can't be body-snatched by spinmeisters; that can make being a crank or a moron seem like a virtue. On the other hand, some voters respond by wanting to get inside the machinery. They demand "behind the scenes" news. Don't tell me about the Constitutional issues involved in the "Ground Zero Mosque" dispute. Tell me how it polls in "Blue Dog Democrat" districts!

These two political tastes—give me a candidate who sounds like Attila the Hun, or give me the candidate's media director, talking strategy—spring from a single source of dissatisfaction: We all know that "activists" out there want to motivate us. And we know that, from far left to far right, what they are saying to us is, to use the technical term, bullshit.

Given the widespread sense that their b.s. approach can't cope with grave national problems, maybe, as Joe Klein suggested the other day, we should chuck what we have now, and replace it completely.