Rights and Duties, the second generation

I was interested in Wellman's discussion of second generation rights - what he eventually names "social welfare rights." Nozick's view of these rights is that they do not have corresponding duties (or perhaps that they do not exist at all as they infringe on the rights of taxpayers not to pay for welfare services for other people). I found this distinctly problematic, though I don't know that I can explain or justify the way I feel about this section (Sorry, I am a feeling person - I tend to know how I feel about issues before I know why I feel that way or how to describe/analyze the problem). My immediate reaction, which merely comes out of personal belief, is that people have a responsibility to assist their brethren when they are capable of doing so. That is, I don't think taxpayers should complain about "their tax dollars" going to public assistance or social welfare programs. Social welfare programs don't just include what people typically think of as "welfare" (providing monetary assistance to people who are living in poverty), but instead it includes public education, public transportation and road construction/repair, the state provides money for people who suffer from mental illness and disabilities when their families cannot afford the costs of medicines and treatments, the state also provides the foster care system and the money used to buy children clothes and provide them with food and other necessities. Many of these services are necessary to the operation of a community - one which recognizes the problems it faces and tries to provide for the people who need the assistance. My problem, then, is that I don't know if these are genuine moral rights. I feel that they are, mostly because in our society, there is an unequal distribution of wealth, education, and opportunity. And, looking at it from the utilitarian view (although I hate that utilitarianism makes commodities of human life), it is better for everyone, even those of us near the top, if these social welfare programs are in place. It's a bit off topic, but I certainly feel better.

So how do we know for sure if something is a moral right? What would it mean to have a legal right that is not morally justifiable? Should it remain a legal right?