In decision, judge relied on facts rather than theory

SAN FRANCISCO — As lawyers last year prepared for the federal case that challenged California's ban on gay marriage, Chief U.S. District Judge Vaughn Walker told both sides he saw his role as a finder of facts who could produce a record that would inform higher courts dealing with constitutional matters.

His ruling Wednesday declaring the ban unconstitutional reflected that inclination. While other rulings on gay marriage have emphasized legal theory, Walker's decision leaned heavily on findings of fact based on the testimony he heard during a 13-day trial in January.

Some legal analysts believe Walker fashioned his order to force judges on the 9th U.S. Circuit Court of Appeals and the U.S. Supreme Court to confront the practical reality of gay unions, rather than treating them as a legal abstraction.

Some analysts also said the reliance on the trial testimony might help Walker's decision survive an appeals court's scrutiny because appellate judges typically give a trial judge's factual findings some deference.

Supporters of the gay-marriage ban filed an appeal Thursday of Walker's decision. The appeal to the 9th U.S. Circuit Court of Appeals was expected. Most legal analysts expect the case will be resolved by the U.S. Supreme Court.

Four conservative justices on the Supreme Court are widely believed to be unlikely to support a decision recognizing a constitutional right of gays to marry.

Four others, including the newly confirmed Justice Elena Kagan, seem more likely to agree with Walker that the Constitution does not allow states to treat gay couples differently from heterosexual ones, analysts said.

The deciding vote, most analysts agree, likely would belong to Justice Anthony Kennedy. In recent years, Kennedy has been the author of two major decisions striking down laws seen as discriminating against gays.

In 2003, he wrote the opinion invalidating a Texas law that made gay sex acts a crime, and in 2007, he struck down a Colorado ballot initiative that prohibited local governments from passing anti-discrimination ordinances based on sexual orientation.

Walker peppered his ruling with numerous citations to Kennedy's two opinions. Some analysts said Walker did not go far enough in trying to allay concerns Kennedy may have about same-sex marriage.

"If you were really trying to be sensitive to Justice Kennedy, you would not be so quick to dismiss the idea of incrementalism," the belief the law should evolve slowly as a nation's views develop, said University of California, Davis, law professor Vikram Amar.

All but five states and the District of Columbia ban same-sex marriage, and the San Francisco jurist's ruling made only an oblique mention that California was part of the national majority on the marriage question, Amar said.

By contrast, Kennedy's previous gay-rights rulings overturned laws that had become "outliers," Amar said. Virtually no states enforced criminal sodomy laws at the time Kennedy invalidated Texas' statute, for example.

Jon Davidson, legal director of Lambda Legal, agreed Walker's factual findings would carry less weight than the kind of straightforward, "whodunit" facts that higher courts let trial judges determine.

But the evidence cited by Walker will "make it harder for higher courts to make the kind of faulty assumptions and speculations that have appeared in other appeals' court rulings," such as the argument that children fare better with opposite-sex parents and that sexual orientation, unlike race, can be changed, Davidson said.

Davidson said he was not confident Walker's decision would win five votes on the Supreme Court.

After ruling Wednesday, Walker signed another order that put his decision on hold until he decides whether same-sex marriages should be permitted pending appeals. Written arguments on that question are due Friday.

Legal analysts said Walker could issue a stay to postpone the effect of his ruling until the 9th Circuit has time to decide whether the decision should be placed on hold.

Joan Heifetz Hollinger, a University of California, Berkeley, law-school lecturer and co-author of a friend-of-the-court brief supporting gay-marriage rights, said Walker was "adamant" in his ruling that "Proposition 8 should be gone."

University of California, Irvine Law School Dean Erwin Chemerinsky said the practical effect of allowing more gay weddings in California may affect whether Walker and higher courts permit Wednesday's ruling to go into effect during time-consuming appeals.

"The longer same-sex marriage occurs in California — the more gay and lesbian couples that are married — the harder it will be ultimately to reverse Walker," the constitutional-law professor said.

Dolan reported from San Francisco and Williams from Los Angeles.