California's Prop. 8 ban on same-sex marriage ruled unconstitutional

California's voter-approved ban on same-sex marriage is unconstitutional, a federal judge in San Francisco has ruled.

Proposition 8, passed by 52% of voters in November 2008, defined marriage as the union of a man and a woman. But after a non-jury trial earlier this year, Chief District Court Judge Vaughn Walker ruled that the initiative violated the equal-protection and due-process clauses of the 14 Amendment of the U.S. Constitution.

After the court announced yesterday that it would issue its ruling today, both sides said they would appeal to the Ninth U.S. Circuit Court of Appeals, also in San Francisco, depending on the outcome. Regardless of how the appeals court rules, the case will reach the U.S. Supreme Court next year or 2012.

Two gay men from Burbank and two lesbians from Berkeley challenged the law, which came in response to a May 2008 state Supreme Court that legalized same-sex marriage. In February 2004, San Francisco's new mayor, Gavin Newsom, approved same- sex marriages, and the city issued about 4,0000 marriage licenses before the state Supreme Court halted the weddings in March. Four months later the court voided all the licenses, prompting lawsuits from gay married couples.

The court set up a special site for the case.

Here's background on the battle over same-sex marriage in California.

Update at 4:58 p.m. ET: In his 136-page opinion, Walker ruled that Proposition 8 "both unconstitutionally burdens the exercise of the fundamental right to marry and creates an irrational classification on the basis of sexual orientation," and that the plaintiffs "seek to have the state recognize their committed relationships, and plaintiffs' relationships are consistent with the core of the history, tradition and practice of marriage in the United States."

Ultimately, Walker concluded, Prop. 8 "fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license. Indeed, the evidence shows Proposition 8 does nothing more than enshrine in the California Constitution the notion that opposite-sex couples are superior to same-sex couples. "