Is not the institution of democracy a creation of the legal system itself? After all, democracy is nothing but a set of procedures of promulgating valid laws - but those procedures themselves are grounded in the supreme law of the land - the constitution. If democracies usually do not have many laws that collide with people's morality or sensibilities it is because people have the institutional capacity to promulgate laws that comply with those sensibilities and repel those that do not. But the same institutional capacity can be used to promulgate laws that are logically contradicting the principles of democracy, cf. Jim Crow.
Another point - what do you mean by "free standing?" All I argued that law does not need justification other than itself (see the above) but that itself does not mean that a law can "stand" without actually being enforced. That means that the only external requirements are enforceability and the power to actualize that enforceability. In other words, the law must be formulated in such a way that it can be enforced, given current state of enforcement technology. A law that proscribes holding evil thoughts about His Majesty is a bad law, because there are no means of enforcing it, but a law proscribing printing those thoughts on paper is a good one, because it can be enforced. Moreover, there must exist the capacity to actually enforce the enforceable law. The law proscribing printing bad things about His Majesty is a joke if HM Censors have no capacity of enforcing it (i.e. manpower to read all that is printed and the capacity to track it to the source).
But beyond the enforceability and the power to enforce what other external justifications of law are there? The only ones that come to mind are natural law or utility - or moral systems that grounded in these two concepts. Enough has been written to thoroughly dismiss both propositions - suffice it to say that utility is insufficient (for otherwise concentration camp would be moral and thus just), and the natural order too vague and ephemeral to be properly defined, let alone empirically determined.
I was under the impression that you were a deontologism sympathizer, no?
Wojtek