WASHINGTON — While lawyers inside the Supreme Court argued over gay marriage Tuesday, hundreds of opponents and supporters gathered outside to dance, sing and pray — and debate the issue.

For the opponents of California’s Proposition 8 ban on gay marriage, which a federal court already had declared unconstitutional, the day was reason for near-celebration, as their cause of equality for same-sex couples had reached the top of the legal system.

“We want our relationships to be recognized as well,” June Crenshaw, 52, of Washington, said of herself and her partner. “It’s the simple things we want to have in our lives.”

For the supporters of the ban, the case was an opportunity to stand firm against an evolving and, to them, disturbing sense of morality that conflicts with their strongly held beliefs.

“As wonderful as it is, it’s not marriage,” John Martin, 51, of Winchester, Va., said of what same-sex relationships.

“Kids do best with a mom & dad!” proclaimed on sign carried by supporters of the ban as they marched up Constitution Avenue after gathering on the National Mall.

“One man! One woman!” they chanted as they approached the court.

The case, Hollingsworth v. Perry, challenges Proposition 8, which California voters approved in 2008 but which was subsequently overturned.

Polls show public opinion shifting in favor of gay marriage.

The justices began hearing the case at midmorning, but the street theater accompanying it had started earlier, even days before, as people began lining up over the weekend for the limited number of tickets to watch the arguments firsthand.

Opponents of Proposition 8 clustered around the courthouse, a massive edifice of classical grandeur, and on the sidewalk across the street near the U.S. Capitol, in a loosely organized rally sponsored by the Human Rights Campaign, a national gay rights organization.

The group instructed participants to wear red, and many did. But so did supporters of the ban, in an opposing march organized by the National Organization for Marriage, a leading supporter of Proposition 8 and the Defense of Marriage Act. The 1996 law, which the Supreme Court will take up Wednesday, prohibits same-sex couples from obtaining federal marriage benefits.

“We all came here to defend traditional marriage,” said Proposition 8 backer Edith Lee, of New York. “They can make their own choices, but they can’t legalize what’s not correct.”

Not far away, Lyssa White, 29, and Kris White, 32, an interracial couple from Manassas, Va., clutched a poster that alluded to a 1967 Supreme Court decision striking down state bans on interracial marriage.

“Not that long ago, our marriage was illegal,” their sign said.

Many people still object to interracial marriage, said Lyssa White, who’s white. “You don’t necessarily have to agree,” said her husband, Kris White, who’s black, “but you have to accept.”

Vincent Herzog, of Gainesville, Fla., a supporter of the ban, echoed the critique that only marriage between a man and a woman can produce children.

“If we don’t have strong families, where’s our country going to be?” he asked.

Opponents contend that’s why same-sex couples should have the right to marry: because it provides family stability. Crenshaw said she had a son with a former partner who was now grown and worked for the FBI, and that there was a time when her family wasn’t recognized as one.

“At that time, I didn’t believe we’d get this far,” she said. “Now we have.”

Faith was a theme in both camps outside the court.

“My belief in the Bible brings me here,” said Felipe Santiago, of New York, who was marching with Proposition 8 supporters. “We’re all going to have to answer to God.”

Across the street, DeWayne Davis, dressed in clergy attire, said a woman had asked whether he was ashamed to be standing among the supporters of gay marriage.

“I said, ‘No, I’m proud. I’m not ashamed,’ “ Davis said. “I don’t ever want to be the one who prolonged or facilitated discrimination.”

Davis, a clergy candidate at Metropolitan Community Church in Washington who grew up in the black Pentecostal church, said it was important to have conversations with other people of faith who hold different views.

“Faith communities are changing all the time,” Davis said.