WASHINGTON -- Last week's debate in the U.S. Senate over a proposed constitutional amendment to define marriage was a case study in the propensity of politicians to cast principle aside to achieve a desired political outcome. In this case the principle was federalism, the relationship between state and federal governments.

		Michael McGough is an editor at large in the PG's National Bureau (mmcgough@ nationalpress.com).

Conservatives, who usually champion states' rights, pressed unsuccessfully for what would have amounted to a national ban on same-sex marriages.

Liberals, who ordinarily treat states' rights as a constitutional relic with racist connotations, turned into fair-weather federalists and carried the day even without John Kerry and John Edwards.

As the Senate was debating a marriage amendment, supporters of states' rights in the legal community were lamenting a 2003-04 U.S. Supreme Court term in which even some conservative justices seemed to be rethinking the idea that Washington has been riding roughshod over the states.

Richard W. Garnett, a law professor at Notre Dame University, told an end-of-term seminar at the American Enterprise Institute that reports of a "federalism revolution" on the court were greatly exaggerated. "If there ever was a revolution, it's over now and indeed is in full retreat," Garnett said.

Yet in the same talk Garnett criticized a decision that other observers are characterizing as pro-state's rights: the court's ruling that the state of Washington did not violate the First Amendment when it chose not to provide college scholarships to students preparing for the ministry.

It would be too cynical to say that all discussions of states' rights are driven by politics. For example, Garnett in his talk made a persuasive case that even for supporters of states' rights the student in Washington made a powerful First Amendment claim. "There's a misunderstanding [that] if one believes in federalism, one believes states can do whatever they want," Garnett said.

The problem is that liberals might use identical language in defending the Supreme Court's ruling, also this term, that Congress could override the states' traditional immunity to lawsuits in federal court by requiring the states to comply with the Americans with Disabilities Act. Yet some of those same liberals object to attempts by the national government to prevent states from experimenting with their own approaches to pollution control, medical marijuana and same-sex marriage.

So often, if not always, appeals to states' rights are arguments of convenience or a form of what lawyers call venue-shopping. The larger question -- whether federalism makes sense in the 21st century -- is fudged. But the question of "why states?" may be moving out of the political science seminar room and into the national conversation, and for reasons unrelated to the debate over gay marriage or the latest Supreme Court ruling on the scope of congressional authority.

The easy answer to "why states?" is that the original 13 colonies came together to form the United States, a phrase once treated as a plural. There are good reasons why Americans say "the United States is," not the "the United States are." One of those reasons is the Union victory in the Civil War, another is the modern economy, and a third is the civil rights movement.

These developments have broken the spell of what Richard Garnett in his talk called the "mystical" understanding of federalism, that the 50 states are "metaphysical entities" deserving of an almost religious deference from Washington. But Garnett pointed out that there are other justifications for state autonomy, including what he called "experimentation federalism."

According to this theory, it is good for states to be able to explore different approaches to public policy. If you don't like that Pennsylvania has legalized slot machines, move to another state.

There is less to this "laboratories of democracy" idea than there used to be, thanks to technological progress (even residents of slot-free states can gamble on the Internet) and thanks to the Supreme Court, which has told states they may not "experiment" with laws against sodomy and interracial marriage.

But this pragmatic argument for federalism works just as well whether there are 50 states or 30 or 20. And it works just as well if the states have an equal say -- as states -- in the national government. But of course they don't. Thanks to the Founding Fathers' belief in what Garnett would call "mystical" federalism, Pennsylvania, with a population of 12,335,091, has two U.S. senators, and so does Delaware with its population of 807,385.

The lack of a one-person, one-vote rule in the composition of the Senate hasn't aroused much outrage at the water cooler. But another constitutional institution reflecting the same theory of state's rights is controversial -- the Electoral College.

Suppose that in 2004, as in 2000, the presidential candidate who wins the popular vote loses in the Electoral College. The pressure for a constitutional amendment to abolish the Electoral College would be immense. The rallying cry would be "People vote, not states." That would be foul weather indeed for federalists of the right or the left and -- who knows? -- it might inspire a more searching debate about states' rights.