WEST HOLLYWOOD -- Southland gay rights advocates Wednesday hailed a decision by a federal judge in San Francisco striking down Proposition 8, the state's voter-approved ban on same-sex marriage.

"Today's historic decision by the federal district court is clearly a milestone victory for all gay, lesbian and bisexual Californians, our families and our friends,'' said Lorri L. Jean, chief executive officer of the L.A. Gay & Lesbian Center.

"But much more than that, it is a resounding affirmation of fundamental American ideals and core principles of the U.S. Constitution.''

U.S. District Judge Vaughn Walker presided over the non-jury trial of a lawsuit alleging that the measure, which was approved by California voters in November 2008, violates the equal protection rights of gay and lesbian couples by preventing them from being married.

In a 136-page ruling, Walker wrote that the proposition "both unconstitutionally burdens the exercise of the fundamental right to marry and creates an irrational classification on the basis of sexual orientation.''

"Proposition 8 fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license,'' Walker wrote. "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.''

Walker issued an order barring the enforcement of the law, but proponents of Proposition 8 were expected to appeal -- likely all the way to the U.S. Supreme Court.

Walker issued a stay on the ruling until at least Friday, meaning same- sex marriages will not immediately resume in the state. Supporters of Prop 8 had asked for a stay, saying allowing couples to marry pending the appeal would create confusion if Walker's ruling is eventually overturned.

Jean conceded that the fight is not over.

"There are more legal challenges, debates and votes to come,'' she said. "Therefore, it is as important as ever that all who support our ultimate goal of full equality continue, through every available avenue and at every opportunity, to persuade those who may not yet be with us.''

Mayor Antonio Villaraigosa praised the ruling, saying the "sun shines a little brighter on the Golden State.''

"A federal judge has affirmed what a majority of Californians already know to be true: that love does not discriminate and that marriage is a civil right, not a privilege reserved for a select class of citizens,'' he said. "The decision handed down today ... reaffirms the notion that separate is never equal.''

Assembly Speaker John Perez, D-Los Angeles, the state's first openly gay Speaker, called the decision "a powerful vindication of our nation's tradition of full equality in the eyes of the law.''

"This is a decision which reaffirms the principles and ideals enshrined in our Constitution, and only serves to underscore the fact that recognition of full equality for LGBT Americans is simply a matter of time,'' Perez said.

Los Angeles County Supervisor Mike Antonovich blasted the ruling.

"To address the issues raised by the courts, Proposition 8 was placed on the ballot after Proposition 22 was deemed unconstitutional by the courts,'' he said. "It is clear that the judge's political correctness agenda prevailed at the expense of the will of the people. Ultimately, it will be up to the United States Supreme Court to uphold the constitutionality of Proposition 8.

"Thomas Jefferson warned that radical judicial activism would undermine the will of the people. He said, `When the people fear their government, there is tyranny.' Today's ruling was a direct assault to the over 4.5 million voters in 2000 and the over 7 million who turned out in 2008 to vote on this vital issue.''

Randy Thomasson, president of SaveCalifornia.com -- Campaign for Children and Families, decried Walker's ruling as "a terrible blow'' to marriage and voter rights.

"Judge Walker has ignored the written words of the Constitution, which he swore to support and defend and be impartially faithful to, and has instead imposed his own homosexual agenda upon the voters, the parents and the children of California,'' Thomasson said. "This is a blatantly unconstitutional ruling because marriage isn't in the U.S. Constitution.

"The Constitution guarantees that state policies be by the people, not by the judges, and also supports states' rights, thus making marriage a state jurisdiction,'' he said.

"... As a Californian and an American, I am angry that this biased homosexual judge, in step with other judicial activists, has trampled the written Constitution, grossly misused his authority and imposed his own agenda, which the Constitution does not allow and which both the people of California and California state authorities should by no means respect,'' he said.

Gov. Arnold Schwarzenegger said the "decision affirms the full legal protections and safeguards I believe everyone deserves'' and "provides an opportunity for all Californians to consider our history of leading the way to the future, and our growing reputation of treating all people and their relationships with equal respect and dignity.''

West Hollywood Mayor John Heilman said the ruling "is a profound statement that LGBT people enjoy the same constitutional protection as all Americans.''

"I am grateful that Judge Walker was able to look past the political controversy and make a legally sound ruling,'' Heilman said."So many people have worked extremely hard for the recognition of LGBT rights, and I am overjoyed that we have achieved this milestone for marriage equality.''

Same-sex marriage supporters gathered in West Hollywood to celebrate the ruling.

In March 2000, California voters approved Proposition 22, which specified in state law that only marriages between a man and a woman are valid in California. But in May 2008, the state Supreme Court ruled the law was unconstitutional because it discriminated against gays, and an estimated 18,000 same-sex couples got married in the ensuing months.

Opponents of same-sex marriage quickly got Proposition 8 on the November 2008 ballot to amend the state constitution, and it was approved by a margin of 52.5 percent to 47.5 percent.

The approval of the measure led to statewide protests and lawsuits challenging the legality of Proposition 8.

In May 2009, the California Supreme Court upheld Proposition 8, but also ruled that the unions of roughly 18,000 same-sex couples who were wed in 2008 would remain valid.

Various gay- and lesbian-rights groups have considered putting the issue back on the ballot, but even the supporters of same-sex marriage have sparred over when to ask voters to reconsider the issue.