Every political community includes some members who insist that their side has all the answers and that their adversaries are idiots. But American liberals, to a degree far surpassing conservatives, appear committed to the proposition that their views are correct, self-evident, and based on fact and reason, while conservative positions are not just wrong but illegitimate, ideological and unworthy of serious consideration. Indeed, all the appeals to bipartisanship notwithstanding, President Obama and other leading liberal voices have joined in a chorus of intellectual condescension.

This condescension is part of a liberal tradition that for generations has impoverished American debates over the economy, society and the functions of government -- and threatens to do so again today, when dialogue would be more valuable than ever.

Starting in the 1960s, the original neoconservative critics such as Daniel Patrick Moynihan expressed distress about the breakdown of inner-city families, only to be maligned as racist and ignored for decades -- until appalling statistics forced critics to recognize their views as relevant. Long-standing conservative concerns over the perils of long-term welfare dependency were similarly villainized as insincere and mean-spirited -- until public opinion insisted they be addressed by a Democratic president and a Republican Congress in the 1996 welfare reform law. But in the meantime, welfare policies that discouraged work, marriage and the development of skills remained in place, with devastating effects.

Ignoring conservative cautions and insights is no less costly today. Some observers have decried an anti-intellectual strain in contemporary conservatism, detected in George W. Bush's aw-shucks style, Sarah Palin's college-hopping and the occasional conservative campaigns against egghead intellectuals. But alongside that, the fact is that conservative-leaning scholars, economists, jurists and legal theorists have never produced as much detailed analysis and commentary on American life and policy as they do today.

Perhaps the most important conservative insight being depreciated is the durable warning from free-marketeers that government programs often fail to yield what their architects intend. Democrats have been busy expanding, enacting or proposing major state interventions in financial markets, energy and health care. Supporters of such efforts want to ensure that key decisions will be made in the public interest and be informed, for example, by sound science, the best new medical research or prudent standards of private-sector competition. But public-choice economists have long warned that when decisions are made in large, centralized government programs, political priorities almost always trump other goals.

Even liberals should think twice about the prospect of decisions on innovative surgeries, light bulbs and carbon quotas being directed by legislators grandstanding for the cameras. Of course, thinking twice would be easier if more of them were listening to conservatives at all.

We see this all too often here. Liberals are so used to living in liberal echo chambers like the Twin Cities that they have lost the ability to even grasp conservative ideas. They then dismiss them as stupid as they have never had to articulate their liberal beliefs before.

Daniel Patrick Moynihan was a Democrat who predicted that welfare would destroy families and subject millions to government servitude. he was correct and liberals are loathe to admit how damaging welfare has been to our society.

Look at the current debates about issues like Cap and Trade and rationing medical care and you will see the same liberal arrogance mixed with ignorance.