Prop 8 and natural law

the following is a reflection I typed up in an email to a few family members:

some thoughts sparked by a LA Times article on the attempts to overturn prop 8 and the counter arguments. My comments follow my excerpt from the Times coverage.
From LA Times article on prop 8 legal battles:
http://www.latimes.com/news/local/la-me-gay-marriage6-2009jan06,0,695679.story
1/6/09

>in a move that outraged supporters of Proposition 8 and took even gay-rights activists by
>surprise, Brown's brief instead urged the court to toss the proposition, declaring that "the
>amendment process cannot be used to extinguish fundamental constitutional rights without
>compelling justification." Brown argued that the California Constitution protects the right
>to marry as inalienable.
...
>Santa Clara University Law professor Gerald Uelmen, an expert on the state high court, said
>it "hits the nail on the head."
>"If you think of the Constitution as a compact between the people and those who govern us,
>to say the people have no power to amend a court's ruling simply because the court . . .
>says this is an inalienable right -- I think that is pretty far out."

From my perspective this is a curious position for conservative Christians to be in--arguing that law is based on the will of the people in this one particular case, when for the most part we are the most outspoken believers in Natural Law. Conversely, it is an odd situation for the other side to be in, arguing that law is not socially constructed but is based on Natural Law. I'm not sure which party should be more uncomfortable.
Behind this, I believe, is the fact that civil rights are the last vestige of Natural Law, the one place in the contemporary social and legal conversation where most people agree that law is based on something higher than case law or some other socially constructed convention. It is ironic to me that many conservative Christians are now willing to embrace for political expedience an argument that basically holds law and the constitution to simply be a reflection of current social opinion. These are the same conservatives who only a few years ago were vociferously arguing that the job of the supreme court is to simply enforce the constitution and that the court errs when it treats the constitution as more malleable.

Do Christians, conservative or otherwise, really want to be making the argument that Ken Star is making in this case? Should we be the ones (I'm not saying Ken Star really is speaking for us, however a lot of Christians support his efforts on behalf of prop 8) making the argument that law is socially constructed? Do we, of all people, not have good reason (historical, doctrinal, philosophical) to continue to hold that the best human law seeks to conform as closely as possible to a higher law, a law which we do not construct at will? Are we justified in making this argument because it is politically expedient, and because we have not been able to win with the argument that homosexuality is against natural law?
This gets back to my earlier concerns that even if religious conservatives manage to pass prop 8 (technically, it has passed) it would come back to bite them in the rear-end in the long run by setting a president of forcing one slim majority opinion on a large minority. As soon as tables switch in this situation, religious conservatives (and even moderates like myself) would be on the receiving end of oppressive laws that enforce the legal opinion of a slim majority against vociferous opposition of a sizable minority.