Apropos of the Marriage Amendment issue: one of the happy accidents of the Bush administration is that the president has been so determined to centralize social policy in the United States that he's actually made some liberals appreciate the virtues of federalism. See this piece by the New Republic's Franklin Foer or this one from Stanford's Richard Thompson Ford for examples.
Early on in his administration, President Bush promised to:
make respect for federalism a priority in this administration. Respect for federalism begins with an understanding of its philosophy. The framers of the Constitution did not believe in an all-knowing, all-powerful federal government. They believed that our freedom is best preserved when power is dispersed. That is why they limited and enumerated the federal government's powers, and reserved the remaining functions of government to the states.
Respect for federalism would require respecting the voters of Oregon when they set up a law allowing terminally ill patients to end their suffering with the help of their doctors. Respect for federalism would require respecting the voters of California and 10 other states that allow cancer patients, AIDS patients and others to use medical marijuana. Yet on these issues and many other issues that the Constitution leaves to the states -- crime, education, marriage -- President Bush has fought very hard to increase Washington's involvement -- usually in ways that offend Blue State sensibilities.
With the Red Team doing the centralizing, it's only natural that the Blue Team would look favorably on a more decentralized system. I've always been a bit uneasy about some of the liberal justifications for federalism, such as Justice Brandeis's "laboratories of democracy" argument. Just who are the lab rats in that metaphor? (Note that Foer lists Elliot Spitzer as one of the bold experimenters liberals should emulate.)
But the virtues of federalism are plain, and appreciating them shouldn't depend on who's up or who's down. Federalism makes it easier for Americans to escape unwelcome state experiments with fiscal and social policy. It enhances the political power of individual citizens by allowing important decisions of governance to be settled closest to where Americans live and work. And it avoids making politics a centralized war of all against all, where each contested moral issue is settled in a one-size-fits-all fashion at the level furthest from the people.
I hope that the Republican assault on federalism leads to a resurgence of decentralist liberalism. I fear that, as with the Right, the Left's interest in subsidiarity will last about as long as its exile from federal power. Yet hope springs eternal.