I was fortunate enough to snag a seat in the press gallery for the oral argument before the U.S. Supreme Court this morning in the Proposition 8 case, Hollingsworth v. Perry.

Prop. 8 was narrowly approved by California voters in 2008. It added a ban on same-sex marriage to the state constitution. Opponents are challenging it in court, asserting that it violates the rights of gays and lesbians who wish to marry.

There were huge crowds outside the court sparring over the issue of marriage equality. In the court chambers, the atmosphere was less noisy but still spirited. But the one thing that struck me most about the debate was the elephant in the room that no one wants to acknowledge: religion.

Gays and lesbians in California found themselves stripped of marriage rights after a campaign spearheaded and funded primarily by the Church of Jesus Christ of Latter-day Saints (the Mormons), the Catholic hierarchy and the Religious Right.

Opposition to same-sex marriage is grounded in theological terms by the Religious Right and their sectarian allies. Marriage equality, we are told, violates God’s law. Yet this is the United States, and under our Constitution, we are not supposed to base our laws on religion.

Americans United and its allies raised this issue in a friend-of-the-court brief, but the justices were not inclined to wrestle with that question this morning. Still, it was a very interesting argument, and I feel lucky to have heard it live.

Charles J. Cooper, the attorney arguing for the pro-Prop. 8 forces, asserted that there is an “earnest debate” over “the age-old definition of marriage.” He called the issue “agonizingly difficult” and insisted that the people should have the right to decide the matter, not the judicial system.

Cooper, like a lot of conservative opponents of marriage equality, linked marriage to procreation. He asserted that “responsible procreation is vital” to society and said same-sex marriage threatens to “sever its historic tie to procreative purposes.”

This sparked a discussion about whether infertile couples and elderly people could be denied the right to marriage. Cooper’s argument sparked some laughter when Justice Elena Kagan asked if a state could bar marriage to people over 55, assuming that they would not procreate. When Cooper asserted that such couples would not necessarily be infertile, Kagan quipped, “I can assure you…there are not a lot of children coming out of that.”

Asked directly by Justice Anthony Kennedy if he contends that same-sex marriage is harmful to society, Cooper said no. (Of course, that’s not the line taken by groups like the Family Research Council.) But Cooper did assert that there will be “real-world consequences” and that some of them might be “adverse consequences.” For example, he insisted that it’s unclear if children are harmed by same-sex parenting.

Theodore B. Olson, U.S. solicitor general in the George W. Bush administration, argued that Prop. 8 should be declared unconstitutional. A long line of court decisions, he argued, makes it clear that marriage is an individual right, not a societal one.

Olson argued forcefully but ran into trouble almost immediately from Justice Antonin Scalia, who demanded to know when same-sex marriage became a constitutional right. Olson was also questioned aggressively by Chief Justice John Roberts, who at one point seemed to argue that if marriage developed as an institution to benefit society, it doesn’t have to include everyone.

One of Olson’s better comebacks came when Justice Samuel Alito asked why civil unions were not enough, asserting that marriage “is just a label.” Olson said that would be like offering inter-racial couples an “inter-racial union” and added, “The label of marriage means something. There are certain labels in this country that mean something.”

In cases dealing with social issues, all eyes and ears tend to be on Justice Kennedy, who is considered a crucial swing vote. Kennedy questioned both attorneys this morning and was careful not to reveal his cards.

At one point, Kennedy noted that 40,000 children in California are being raised by same-sex parents and told Cooper that he is concerned about them.

“The voice of those children is important to this debate, don’t you think?” he asked, adding, “They want their parents to have the full recognition [of marriage].”

But Kennedy also badgered Olson, asserting that his argument was too broad and fretting that the court was being asked to “go into uncharted waters.” At one point, Kennedy even seemed to regret that the case was before the court, musing, “I just wonder if this case was properly granted?” (His remark drew a rebuke from Scalia, who snapped, “We’ve crossed that river!”)

I’m not an attorney and can’t say what will happen with this case. The court, however, has a way to dodge the case if it wants it. Since California’s state officials declined to defend Prop. 8 in court, the matter was turned over to a private entity.

If the Supreme Court decides that the private group had no right to act for the state and appeal Prop. 8, the court could toss the case entirely without even ruling on the constitutionality of same-sex marriage. If this happens, a lower court decision striking down Prop. 8 will go back into effect – but the ruling will be limited to California.

That would give the justices the option of avoiding a decision that sets a national precedent, something several of them seemed uneasy about doing. Some justices even asserted that same-sex marriage is too new of a concept to be before the high court.

If the court takes this avenue to avoid the issue, the question of the constitutionality of same-sex marriage will have to wait for another day.

P.S. Audio of the argument can be found here.