Rothbard, in For A New Liberty:
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.
Rockwell, from The Calamity of Bush’s Conservatism:
What does conservatism today stand for? It stands for war. It stands for power. It stands for spying, jailing without trial, torture, counterfeiting without limit, and lying from morning to night. There comes a time in the life of every believer in freedom when he must declare, without any hesitation, to have no attachment to the idea of conservatism.
Rockwell, from The Enemy Is Always the State:
Let me state this as plainly as possible. The enemy is the state. There are other enemies too, but none so fearsome, destructive, dangerous, or culturally and economically debilitating. No matter what other proximate enemy you can name – big business, unions, victim lobbies, foreign lobbies, medical cartels, religious groups, classes, city dwellers, farmers, left-wing professors, right-wing blue-collar workers, or even bankers and arms merchants – none are as horrible as the hydra known as the leviathan state. If you understand this point – and only this point – you can understand the core of libertarian strategy.
See also my post The Nature of the State and Why Libertarians Hate It.