Jeff Zarrillo ( L) and Paul Katami, plaintiffs in the case against California's gay marriage ban known as Prop 8, talk to reporters outside the Supreme Court in Washington, June 26, 2013. On Wednesday the the Court handed a significant victory to gay rights advocates by recognizing that married gay men and women are eligible for federal benefits, paving the way for same-sex marriage in California. [Photo/Agencies]

'SECOND-CLASS CITIZENS'

Gay marriage advocates celebrated outside the courthouse. A big cheer went up as word arrived DOMA had been struck down. "DOMA is dead!" the crowd chanted, as couples hugged and cried.

Paul Katami and Jeffrey Zarrillo, a gay couple from Burbank, California, who were two of the four plaintiffs in the Proposition 8 case, were both outside the courthouse.

"We are gay. We are American. And we will not be treated like second-class citizens," Katami said.

He turned to Zarrillo, voice cracking and said: "I finally get to look at the man I love and say, 'Will you marry me?'"

Before Wednesday, 12 of the 50 US states plus the District of Columbia recognized gay marriage. Three of those dozen - Delaware, Minnesota and Rhode Island - legalized gay marriage this year. California would become the 13th state to allow it.

About a third of the US population now lives in areas where gay marriage is legal, if California is included.

"We are a people who declared that we are all created equal, and the love we commit to one another must be equal as well," Obama, the first sitting president to endorse gay marriage, said in a written statement.

While the ruling on DOMA was clearcut, questions remained about the meaning of the Proposition 8 ruling for California. Proposition 8 supporters vowed to seek continued enforcement of the ban until litigation is resolved. But California Governor Jerry Brown, a Democrat, said the justices' ruling "applies statewide" and all county officials must comply with it.

"We are now faced with this unusual situation where we have some uncertainty," said Andrew Pugno, one of the Proposition 8 proponents' lawyers. He expressed satisfaction that the Supreme Court had "nullified" a San Francisco-based 9th US Circuit Court of Appeals ruling that, if left intact, could have had set a precedent for other Western states in its jurisdiction.