Robert Draper’s long magazine piece about the possibility of a “libertarian moment” has drawn a fair bit of commentary; much of it involves questioning the supposed polling evidence. As Jonathan Chait points out, independent polling — as opposed to surveys conducted by libertarians seeking to boost their own profile — suggests that young Americans are actually much more pro-government than their elders. They may look relatively kindly on anti-war libertarians, but they really don’t support the policy agenda.

But there’s what I would consider an even bigger problem: when it comes to substance, libertarians are living in a fantasy world. Often that’s quite literally true: Paul Ryan thinks that we’re living in an Ayn Rand novel. More to the point, however, the libertarian vision of the society we actually have bears little resemblance to reality.

Mike Konczal takes on a specific example: the currently trendy idea among libertarians that we can make things much better by replacing the welfare state with a basic guaranteed income. As Mike says, this notion rests on the belief that the welfare state is a crazily complicated mess of inefficient programs, and that simplification would save enough money to pay for universal grants that are neither means-tested nor conditional on misfortune. But the reality is nothing like that. The great bulk of welfare-state spending comes from a handful of major programs, and these programs are fairly efficient, with low administrative costs.

Actually, the cost of bureaucracy is in general vastly overestimated. Compensation of workers accounts for only around 6 percent of non defense federal spending, and only a fraction of that compensation goes to people you could reasonably call bureaucrats.

And what Konczal says about welfare is also true, although harder to quantify, for regulation. For sure there are wasteful and unnecessary government regulations — but not nearly as many as libertarians want to believe. When, for example, meddling bureaucrats tell you what you can and can’t have in your dishwashing detergent, it turns out that there’s a very good reason. America in 2014 is not India under the License Raj.

In other words, libertarianism is a crusade against problems we don’t have, or at least not to the extent the libertarians want to imagine. Nowhere is this better illustrated than in the case of monetary policy, where many libertarians are determined to stop the Fed from irresponsible money-printing — which is not, in fact, something it’s doing.

And what all this means in turn is that libertarianism does not offer a workable policy agenda. I don’t mean that I dislike the agenda, which is a separate issue; I mean that if we should somehow end up with libertarian government, it would quickly find itself unable to fulfill any of its promises.

So no, we aren’t about to have a libertarian moment. And that’s a good thing.