"In short, the term "utopian" in popular parlance confuses two kinds of obstacles in the path of a program radically different from the status quo. One is that it violates the nature of man and of the world and therefore could not work once it was put into effect. This is the utopianism of communism. The second is the difficulty in convincing enough people that the program should be adopted. The former is a bad theory because it violates the nature of man; the latter is simply a problem of human will, of convincing enough people of the rightness of the doctrine. “Utopian” in its common pejorative sense applies only to the former.
In the deepest sense, then, the libertarian doctrine is not utopian but eminently realistic, because it is the only theory that is really consistent with the nature of man and the world. The libertarian does not deny the variety and diversity of man, he glories in it and seeks to give that diversity full expression in a world of complete freedom. And in doing so, he also brings about an enormous increase in productivity and in the living standards of everyone, an eminently “practical” result generally scorned by true utopians as evil “materialism.”
The libertarian is also eminently realistic because he alone understands fully the nature of the State and its thrust for power. In contrast, it is the seemingly far more realistic conservative believer in “limited government” who is the truly impractical utopian. This conservative keeps repeating the litany that the central government should be severely limited by a constitution. Yet, at the same time that he rails against the corruption of the original Constitution and the widening of federal power since 1789, the conservative fails to draw the proper lesson from that degeneration.
The idea of a strictly limited constitutional State was a noble experiment that failed, even under the most favorable and propitious circumstances. If it failed then, why should a similar experiment fare any better now? No, it is the conservative laissez-fairist, the man who puts all the guns and all the decision-making power into the hands of the central government and then says, “Limit yourself”; it is he who is truly the impractical utopian.”
— Murray N. Rothbard, The Case for Radical Idealism