The “reality-based community” isn’t what it used to be.

Progressives spent much of the George W. Bush years deriding the right for disdaining reality itself and waging an associated “war on science,” such was its purported hostility to evidence. The meme arose from a highhanded blind quote from a Bush senior adviser to journalist Ron Suskind; the adviser said that people in the “reality-based community” underestimated how the United States could alter the state of things through the exercise of its power.

The left happily adopted the appellation “reality-based community.” It congratulated itself on its factual rigor and nominated for president a man whose initial appeal was based, in part, on his exquisite sense of nuance. Message: We’re more empirically grounded and intellectually supple than you.

The erstwhile reality-based community is having a tough time of it lately, though. Most infamously, Obamacare is foundering on the flagrant deceptions used to sell it, exposed every day by the workings of the law in reality.

Many liberals still don’t want to acknowledge the rather straightforward fact that if you mandate more insurance benefits in the so-called Affordable Care Act, insurance will cost more. Q.E.D. You might be able to cushion the cost increase for some people with subsidies, but not for everyone, and the underlying insurance is still more — not less — expensive.

New York Times columnist Paul Krugman wrote a particularly smug op-ed titled “The Wonk Gap” a couple of months ago, celebrating the left’s lopsided advantage in policy analysis at the same time he pooh-poohed and took as a sign of rank ignorance the Republican contention that there would be sticker shock from Obamacare.

Krugman must consider it in extremely poor form that his own paper is kowtowing to the ignoramuses by publishing stories on how couples like Mike and Kay Horrigan of North Carolina are faring under the Affordable Care Act: “Mr. Horrigan’s coverage by a state high-risk insurance program was eliminated, then replaced by a more expensive plan. His wife’s individual plan was canceled for being substandard, then suddenly renewed — also at a higher price.”

The deceptions around Obamacare are central — both to the law and to the left’s advocacy generally. So much of liberal policy is based on Affordable Care Act-style thinking, which involves hiding and never acknowledging the costs of a given policy; giving legislation a warm and fuzzy name on the assumption that its results will live up to that label; and moralistic attacks on people who resist as fools and ogres.

Every side in a political argument tends to gild the lily, but the acknowledgment of any downside is particularly devastating to liberal presumptions. Liberals are inherently activists on domestic policy, and to make the strongest possible case for action, you need certainty, not nuance; cost-free benefits, not painful trade-offs; blissful promises, not unintended consequences.

Consider the minimum wage. Rarely do liberals truly grapple with the possibility — supported by some, but not all research — that it suppresses employment. If they did, they would be more cautious about advocating a higher minimum wage in a soft job market, and less scornful of opponents.

When Sen. Rand Paul, R-Ky., said the other day that extended unemployment benefits could keep people from searching for a job, he was denounced, literally, as a Scrooge. It doesn’t matter that there is plenty of evidence — some of it once mustered by Alan Krueger, the former head of the White House Council of Economic Advisers — on Paul’s side. He is presumed guilty of a moral failing.

The 19th-century laissez-faire thinker William Graham Sumner famously wrote of “the forgotten man” who bears the costs of feel-good economic policy. Sumner said that “he is the man who never is thought of. He is the victim of the reformer, the social speculator, and philanthropist.” The left must always pretend he doesn’t exist — and excoriate those mindful of him — even as it prides itself on its robust empiricism.

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.