The ideas of the center-left — based on welfare states conjoined with market economies — have been deployed all over the democratic world, most extensively in the social democratic Scandinavian countries. We also have had deadly experiments with communism, a.k.a Marxism-Leninism.

From this, Lind asks another question: “If socialism is discredited by the failure of communist regimes in the real world, why isn’t libertarianism discredited by the absence of any libertarian regimes in the real world?”

The answer lies in a kind of circular logic: Libertarians can keep holding up their dream of perfection because, as a practical matter, it will never be tried in full. Even many who say they are libertarians reject the idea when it gets too close to home.

The strongest political support for a broad anti-statist libertarianism now comes from the tea party. Yet tea party members, as the polls show, are older than the country as a whole. They say they want to shrink government in a big way but are uneasy about embracing this concept when reducing Social Security and Medicare comes up. Thus do the proposals to cut these programs being pushed by Republicans in Congress exempt the current generation of recipients. There’s no way Republicans are going to attack their own base.