She hedges her bets as well in another column:
But for some opponents of same-sex marriage, even the federal and state DOMAs are not reassurance enough. Some of these people worry that the federal law may someday be invalidated as inconsistent with the full faith and credit clause. That's why they seek an amendment to the U.S. Constitution. But the law is probably not unconstitutional. (Granted, that is not a very high recommendation.) Even if constitutional, it is a silly law, motivated by nothing but political grandstanding.
She has an opinion on it, and she's certainly qualified to have one, but her opinion is hardly the final word.
Actually, after responding to gbaji, I googled a little and read where other states had to recognize interracial marraiges not because of full faith & credit, but because of the Equal Protections Act.
Equal Protection is another area DOMA is being attacked from, as well as the Tenth Amendment, from which states have the authority to determine who is married (in regards to receiving federal benefits).
Some law blog regarding the Mass. DOMA decision wrote:
The Judge then merged the Tenth Amendment and Spending Clause challenges - - - "two sides of the same coin" - - - although specifically discussing and applying the classic spending clause case of South Dakota v. Dole. The Judge found that DOMA "plainly intrudes on a core area of state sovereignty—the ability to define the marital status of its citizens," and applied First Circuit precedent regarding the test for a Tenth Amendment analysis
Judge Tauro outlined the plaintiffs arguments that the classification should merit strict scrutiny under equal protection clause doctrine, but held that the court “need not address these arguments, however, because DOMA fails to pass constitutional muster even under the highly deferential rational basis test,” because “there exists no fairly conceivable set of facts that could ground a rational relationship” between DOMA and a legitimate government objective, and that therefore DOMA violates the core constitutional principles of equal protection.
Edit: I will happily admit though that I overstated the current effect of the Full Faith & Credit Clause in regards to marriage. Edited, Jun 27th 2011 1:56pm by Jophiel