I begin from a different point, from the observations that we Americans alive today are all the recipients of an extraordinary and unmerited gift, an inheritance of institutions, principles, and organizations that is without peer anywhere on the world today and that is of inestimable value. We aren't independent liberal individuals making a social contract in the rational light of Enlightenment Reason. Instead, we are heirs who have received an enormous inheritance from our predecessors. As Burke wrote, we "claim and assert our liberties as an entailed inheritance derived to us from our forefathers, and to be transmitted to our posterity--as an estate specially belonging to the people." It's not a contract, or if it is a contract it is not one just between those alive today. Again, as Burke puts it, if you are to think of a social contract you have to recognize that it is not "a partnership agreement in a trade of pepper and coffee, calico, or tobacco, or some other such low concern, to be taken up for a little temporary interest, and to be dissolved by the fancy of the parties.... It is a partnership in all science; a partnership in all art; a partnership in every virtue and in all perfection. As the ends of such a partnership cannot be obtained in many generations, it becomes a partnership not only between those who are living, but between those who are living, those who are dead, and those who are to be born."
The rest of the post is more partisan, so your mileage may vary, but I think all of it is very good.
I should once again reiterate that this has major implications for immigration policy, which I consider to be the greatest civil rights issue of our day.