In a decision with enormous legal, political, and religious implications, a federal judge on Wednesday (Aug. 4) struck down California’s voter-approved ban on same-sex marriage.

Chief U.S. District Judge Vaughn Walker’s watershed decision marks the first time a federal judge has declared a state gay marriage ban unconstitutional.

In a 138-page decision, Walker ruled that “moral and religious views” are not a “rational basis” for the state to deny same-sex couples equal marriage rights.   

Walker concluded that Proposition 8, California’s voter referendum that outlawed gay marriage in 2008, violates the constitutional rights of gay and lesbian couples.

“Proposition 8 fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license,” Walker said. “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’s ruling will be appealed, and the lawsuit, brought by two same-sex couples and the city of San Francisco, could eventually reach the U.S. Supreme Court.

Including California, 29 state constitutions bar same-sex marriage. Twelve additional states have laws restricting marriage to one man and one woman. Same-sex marriage is legal in five states and the District of Columbia.

While Walker’s ruling technically applies to California, it will have wider implications as the case moves up the federal judicial ladder — a fact ruefully acknowledged by conservative activists.

Tony Perkins, president of the conservative Family Research Council, warned that “this lawsuit, should it be upheld on appeal and in the Supreme Court, would become the ‘Roe v. Wade’ of same-sex marriage, overturning the marriage laws of 45 states.”

Even before the decision was made public, the religious and conservative groups that pushed for Proposition 8 asked for a stay of Walker’s ruling and vowed to appeal it.

The case pitted same-sex couples, who argued that gay marriage ban violated their constitutional rights to equal protection, against religious groups and conservatives who countered that the traditional definition of marriage — and the votes of 7 million Californians who favored the ban — should stand.

California voters supported Prop 8 by a margin of 52-48 percent in 2008, just five months after the state’s Supreme Court legalized gay marriage.

Walker said the plaintiffs offered “overwhelming evidence” the gay marriage ban violates their rights to due process and equal protection under the law. He also noted California issued 18,000 marriage licenses to gay couples in the five months gay marriage was legal and “has not suffered any demonstrated harm as a result.”

Religious groups — including the Roman Catholic Church and the Church of Jesus Christ of Latter-day Saints — used their political influence and deep pockets to push for Prop 8. Mormons gived an estimated $22 million to the cause, and church headquarters were fined $5,000 by California officials for failing to declare non-monetary contributions.

“The evidence shows conclusively that moral and religious views form the only basis for a belief that same-sex couples are different from opposite-sex couples,” Walker writes in his decision. “The evidence fatally undermines any purported state interest in treating couples differently; thus, these interests do not provide a rational basis for supporting Proposition 8.

Religious conservatives lamented Wednesday’s ruling. “Traditional Jewish values recognize marriage as being only between a man and woman,” said the Union of Orthodox Jewish Congregations of America in a statement.

“In addition to our religious values — which we do not seek to impose on anyone — we fear legal recognition of same-sex marriage poses a grave threat to the fundamental civil right of religious freedom.”

But a recent poll sponsored by advocates for gay equality suggests public opinion in California has shifted in favor of allowing same-sex couples to wed.

Just 22 percent of Californians believe passing Prop 8 was a good thing for the state, according to a poll conducted in June by Public Religion Research Institute, a non-partisan organization based in Washington.

A slight majority — 51 percent — said they would vote to allow gay and lesbian couples to marry if another vote were held. The poll was sponsored by the Evelyn & Walter Haas, Jr. Fund, to “survey California religious communities and help develop religious education strategies supporting gay equality.”

Support for expanding the definition of marriage remains tepid nationwide, though, with just 39 percent of Americans saying gay marriage should be legal, according to a joint poll conducted in April by CBS News and The New York Times.

But gay rights advocates appear to be on a winning streak, after a federal judge in Boston last month struck down part of the 1996 Defense of Marriage Act, a federal law that defines marriage as the union of one man and one woman, and enables states not to recognize same-sex relationships as marriages.