SAN FRANCISCO (AP) — A judge ruled yesterday that California’s ban on gay marriage is unconstitutional — a legal milestone that, if upheld on appeal, would open the way for the most populous state to follow Massachusetts in allowing same-sex couples to wed.
Judge Richard Kramer of San Francisco County’s trial-level Superior Court likened the ban to laws requiring racial segregation in schools, and said there appears to be ‘‘no rational purpose’’ for denying marriage to gay couples.
The ruling came in response to lawsuits filed by the city of San Francisco and a dozen gay couples a year ago after the California Supreme Court halted a four-week same-sex marriage spree started by Mayor Gavin Newsom.
The opinion had been eagerly awaited because of San Francisco’s historical role as a gay rights battleground.
Gay marriage supporters hailed the ruling as a historic development akin to the 1948 state Supreme Court decision that made California the first state to legalize interracial marriage.
‘‘Today’s ruling is an important step toward a more fair and just California that rejects discrimination and affirms family values for all California families,’’ San Francisco City Attorney Dennis Herrera said.
At issue were a 1977 law that defined marriage as ‘‘a personal relation arising out of a civil contract between a man and a woman,’’ and a voter-approved measure in 2000 that amended the law to say more explicitly: ‘‘Only marriage between a man and a woman is valid or recognized in California.’’
The state maintained that tradition dictates that marriage should be limited to opposite-sex couples. Attorney General Bill Lockyer also cited the state’s domestic-partners law as evidence that California does not discriminate against gays.
But Kramer rejected that argument, citing Brown v. Board of Education — the landmark U.S. Supreme Court decision that struck down segregated schools.
‘‘The idea that marriage-like rights without marriage is adequate smacks of a concept long rejected by the courts — separate but equal,’’ the judge wrote.
It could be months or years before the state actually sanctions same-sex marriage, if ever.
Robert Tyler, an attorney with the conservative Alliance Defense Fund, said the group would appeal. And Lockyer has said in the past that he expected the matter eventually would have to be settled by the California Supreme Court.
Last winter, nearly 4,000 gay couples got married after Newsom instructed the city to issue them licenses. The California Supreme Court later declared those marriages void, saying the mayor overstepped his authority. But the court did not address the underlying issue of whether the law against gay marriage violates the California Constitution.