I’m happy to go another round with Jonathan. Maintaining the same numerical order, here are my replies:
1. I do not dispute that marriage has, in large measure, traditionally been the province of the states. Through the 19th century enabling acts barring polygamy, Congress demonstrated what ought to be obvious—that marriage is nonetheless a matter of national interest and that basic threats to marriage deserve a national response. The relevant question is whether same-sex marriage presents such a threat. Too many opponents of the federal marriage amendment, it seems to me, try to duck that question by pretending that the existing division of constitutional authority is somehow sacrosanct.
Setting aside any quibbling over adjectives, I agree that those proposing an amendment have the burden of making the case that the amendment is appropriate. As the articles that I have cited show, I believe that same-sex marriage presents an extreme threat to the central social institution of American civilization. I respect the fact that others disagree. But let’s have the debate. Jonathan evidently believes that same-sex marriage does not present an extreme threat, but he has not given me even a hint of his thinking on this central question. (But perhaps he has done so elsewhere.)
I’m not sure what Jonathan means when he says that the traditional division of responsibilities “should only be altered in the most extreme circumstances”. Do we need to wait for all the harm to occur (when it’s then too late to remedy the damage)? If the Thirteenth Amendment could have been promulgated and ratified before the Civil War, would Jonathan argue that laws governing slavery were the traditional province of the states and that the circumstances were not yet extreme enough to warrant an amendment?
2 and 4. Jonathan seems to transmute my proposition that there is a national interest in a matter into the different proposition that the matter is a federal question. Again, I think the relevant question for purposes of a constitutional amendment is whether states are doing, or threatening to do, something so damaging to the national interest that an amendment is warranted. (Not incidentally, when the state action occurs through the lawless decisions of state judges, the traditional values of federalism seem to me to have very little weight, especially in the face of Article IV, section 4’s “guarantee to every State in this Union [of] a Republican Form of Government.”)
The very process of amending the Constitution (which requires a three-fourths vote of all the states) ensures ample respect for traditional state interests.
3. If Article V, under Jonathan’s logic, doesn’t create a federal nexus, then neither does the conferral of power on Congress to admit new states. In other words, Jonathan’s theory can’t accommodate the enabling acts barring polygamy (which perhaps is why his original response didn’t list them as examples where there was a clear federal nexus).
One final, larger point: Libertarians make very important contributions to public policy, but it seems to me that too many are blind to the accumulation of moral capital in a society that makes it possible to have limited government—and to the possibility of rapid and permanent depletion of that moral capital. The traditional institutions of marriage and the family are the best means discovered for building up that moral capital and producing citizens capable of self-government. As the damage already done to those institutions in recent decades shows, well-intentioned reforms (e.g., no-fault divorce and welfare policies that inadvertently encourage fatherless families) can have dramatic negative consequences.