Libertarians are widely seen as welfare-state abolitionists - people who want to eliminate government's "safety-net" role, not make it more efficient. Will Wilkinson rightly points out that many well-known intellectuals in the libertarian camp - including Friedman, Hayek, and Buchanan - didn't share the abolitionist position, and suggests that it might be time for libertarians to drop their extremism and get real:
The death of socialism as a viable competitor to the liberal-capitalist welfare state makes continued slippery-slope-to-socialism thinking look densely anachronistic. Other liberal welfare states, like the UK, Sweden, Denmark, Australia, New Zealand, etc., have moved in a rather more market-liberal direction, becoming rather less of a soft-socialist middle-ground between the American model and full-on economic socialism... In this context, the negative income tax looks much less like a dangerous concession to the world-historical forces of evil.
Will's right about Friedman, Hayek, and Buchanan, and right about the slippery-slope argument. But I still think that welfare-state abolitionism has the force of argument on its side.
First, though I'm not going to win Will over to "Ayn Rand and Murray Rothbard’s peculiar views of rights and coercion," the welfare state is an area where it's particularly apt. Almost no one thinks you should be legally required to financially assist your relatives - even your indigent parents who raised you. The welfare-state abolitionist can fairly ask all of these people a tough question: If your parents shouldn't have a legal right to your help when they really need it, why should complete strangers?
Second, and probably even more compellingly, the existence of welfare state is one of the main rationalizations for undercutting the greatest anti-poverty campaign the world has ever known: immigration. (Friedman said it most clearly: "You cannot simultaneously have free immigration and a welfare state." But Krugman's in full agreement). And unlike the welfare state, immigration has and continues to help absolutely poor people, not relatively poor Americans who are already at the 90th percentile of the world income distribution. There's no reason for libertarians to make apologies to social democrats: Libertarian defenders of immigration are the real humanitarians in the world, and the laissez-faire era of open borders without the welfare state was America's real humanitarian era.
Now I'm the first person to say that there are better ways to save the welfare state than curtailing immigration. If that's your worry, let immigrants come as guest workers - entitled to work but not collect welfare. At the same time, though, the presence of guest workers does reveal the hollowness of the standard rationales for the welfare state. It's hard to keep prating about how much you love "the poor" while insisting that the elderly Haitian who shines your shoes shouldn't get a dime.