Round two of the Supreme Court's discussion of same-sex marriage this week finds the highest court in the land debating the constitutionality of the Defense of Marriage Act, one of the more questionable decisions President Clinton made while in office.

Justice Kennedy, who declined to give an opinion either way on Proposition 8 yesterday, swung to the left this morning, joining the liberals in questioning why anyone would defend the law that defines marriage as only between a man and a woman for federal benefits programs. From the New York Times:

'The question is whether or not the federal government under a federalism system has the authority to regulate marriage,' Justice Kennedy said during oral arguments, suggesting that the question should be left to the states. He disagreed with the contention that the federal law simply created a single definition for federal purposes, noting that same-sex couples are not treated the same as other married couples. 'It’s not really uniformity,' he said.

Ruth Bader Ginsberg, who totally called this back in September, showed off her playful side saying DOMA effectively created two kinds of marriage: "Full marriage and the skim-milk marriage.”

Attorney Paul Clement spoke on behalf of House Republicans (or just John Boehner), telling the court that the federal government "a legitimate interest" in the debate. Using a tired defense, Clement told the court that lawmakers were concerned if one state expanded the definition of marriage to include same-sex couples it would effectively force other states recognize them as well.

On the conservative side of the bench, Chief Justice Roberts was apparently irritated that the case made it to the Supreme Court at all. President Obama has declared the act unconstitutional, but continues to enforce it until the Supreme Court weighs in. It's a wishy-washy tactic by the Obama Administration, and Roberts called him on it, saying the President should "have the courage of his convictions" and not enforce the law.

Regardless, SCOTUSblog sees this one turning out very well for gay rights advocates and not so well for the Defense of Marriage Act:

A PDF transcript of this morning's oral arguments can be found here. Audio is available here.