Opponents of Prop. 8 demonstrate outside of the U.S. 9th Circuit Court of Appeals on Tuesday in San Francisco. (Justin Sullivan / Getty Images)
The U.S. 9th Circuit Court of Appeals in San Francisco on a 2-to-1 vote Tuesday upheld a lower court ruling, which had declared California's controversial Proposition 8 ban on same-sex marriage unconstitutional .
The matter is now expected to travel to the U.S. Supreme Court.
The court also ruled that Judge Vaughn Walker, the U.S. District Judge who in August 2010 ruled that Prop 8 was unconstitional, did not need to recuse himself because he is gay.
"Proposition 8 serves no purpose, and has no effect, other than to lessen the status and dignity of gays and lesbians in California, and to officially reclassify their relationships and families as inferior to those of opposite-sex couples," the ruling states. "The Constitution simply does not allow for 'laws of this sort.'"
The ruling was made by judges Stephen Reinhardt, Michael Daly Hawkins and Randy Smith -- appointed by Jimmy Carter, Bill Clinton and George W. Bush, respectively. It is considered one of the most liberal court in the country.
Smith, expectedly, was the dissenting vote on constitutionality.
"Alternately, I am not convinced that Proposition 8 is not rationally related to a legitimate governmental interest," he wrote. "I must therefore respectfully dissent."
The judges heard oral arguments on the constitutionality question more than a year ago. They heard arguments on the recusement in December.
California voters agreed to Prop 8 -- also known as the California Marriage Protection Act -- in November 2008 by a 52 to 47 percent margin (approximately 13 million voters took part). That vote inserted language in the state constitution expressly allowing marriage only between a man and a woman.
Two same-sex couples challenged the vote, and in 2010 retired U.S. Federal Court Judge Vaughn Walker declared the proposition unconstitutional because it denied equal protection under the law. However, Prop 8 supporters argue that because Walker later acknowledged that he is gay, it was improper for him to rule on the matter.
The California Supreme Court upheld the validity of the voter initiative, and a stay has been in place on Prop 8 pending appeals.
California Gov. Jerry Brown told CNN when he was attorney general in 2009 that he expected gay marriage to return to the state after the issue was likely decided by the highest court in the land.
"It is very hard to say, well, some get it and some don't when there's no real basis for the distinction. I think that's where the law is evolving at this point," said Brown.