Either this is a telling argument against libertarianism or I'm missing or mistaking things.
....Larry, I tried this out, with a lot of help along the way, on someone I know. So If you don't mind I want to try a different tack with you, turning on the difference between aptness and legitimacy.
Nozick argues that independents are to be forcibly incorporated into society. Even if their rejection of it is their right, they pose a danger to what they reject (thus on a utilitarian basis decreasing the happiness of those accepting society by increasing their fear.) They can live in society obeying its laws or be dealt with by the monopolizer of force if their rejection leads to law breaking and worse. Since ought entails can, there is no moral duty to do the impossible. On this basis, the state does not lose legitimacy by that forcible incorporation: it is impossible to deal with the independents otherwise. In one way of understanding this, that incorporation comes down to the sheer power of the state compared to the relative powerlessness of the independents.
Now, to take this one step further, what if a majority in the state want national health insurance. (Getting it increases their happiness.) What position can the minority take who oppose but are perforce required to help fund it through their taxes, or, even more pervasive, the welfare state? Does the state lose its legitimacy by forcing those opposed to support them by making them pay their taxes? Does the reasoning for the forcible incorporation of the independents without sacrificing legitimacy lose its force in relation to forcing dissenters from welfarism without, the argument is, by analogy, losing legitimacy? I'd think that those who oppose welfarism would continue to insist on their opposition but would do so conceding legitimacy.
So if Nozick is:
as I understand he is, a social contract theorist;
and if he agrees that the basis of social contract theory is consent;
and if he rejects any proposition, as I understand he does, advanced by some that since unanimous consent in any state is impossible the state, any state premised on deep individual pluralism is therefore necessarily illegitimate;
then his notions of consent and legitimacy necessarily brook majorities that hold to policies that he stands fundamentally against.
If so, then what exactly is the core of his notion of legitimacy, and what does that core do to the illegitimacy of the welfare project you argue against? Arguments pro and con specific policies on the basis of legitimacy run up against the concession of legitimacy to the state even as majority policies breach libertarians' central thesis of deep pluralism not to be trenched upon. And so, finally, arguments against say welfare policy can cite that central thesis, but can't with consistency, I don't think, assert the illegitimacy of that policy. Or can they?
No doubt there are frailties in this reasoning. I'd be happy to see that set out, as you see it...