The city of San Francisco told a federal appeals court today that "Proposition 8 is peculiarly irrational under California law."
Lawyers for the city made the argument in a brief asking the 9th U.S. Circuit Court of Appeals to uphold an August ruling in which U.S. District Judge Vaughn Walker struck down California's ban on same-sex marriage.
Supporters of the ban, enacted by state voters as Proposition 8 in 2008, have appealed to the 9th Circuit. The appeals court will hear arguments in San Francisco in early December and in the meantime has stayed Walker's ruling.
In an appeal brief filed in September, Proposition 8 sponsors argued the measure was justified to promote "responsible procreation and child-rearing" by biological parents within heterosexual marriages.
But that reasoning makes no sense because California law treats gay and lesbian parents the same as heterosexual parents and makes no distinction in the rights and responsibilities of biological and adoptive parents, city lawyers argued today.
"There is no suggestion in any of the California statutes or cases governing parentage that same-sex couples are any less fit to be parents than opposite-sex couples or any policy preference for opposite-gendered parenting," city lawyers wrote.
Since Proposition 8 didn't change any of those laws, the city lawyers argued, it "is not rationally related to legitimate government interests" in California.
"When you look at California laws governing families and parenting, the hypothetical reasons proponents offer to justify Proposition 8 just don't add up," city attorney Dennis Herrera said.
The city lawyers said they also support two broader arguments scheduled to be made in a separate brief due by midnight tonight from the two same-sex couples who filed the lawsuit decided by Walker.
Yusef Robb, a spokesman for the two couples' lawyers, said the plaintiffs' brief would be filed later tonight.
Those arguments are that Proposition 8 violates the federal constitutional rights of equal treatment and due process. Walker based his Aug. 4 decision on his conclusion that Proposition 8 violated those two constitutional guarantees.
But the city's argument that Proposition 8 is irrational under California law would offer the appeals court a narrower ground for upholding Proposition 8, in a ruling that might be restricted to California's situation.
Proposition 8 supporters have until Nov. 1 to file a reply to today's briefs.
A three-judge panel of the appeals court will hear the case during the week of Dec. 6. The date will be announced about six weeks beforehand, and the names of the judges will be announced about 10 days in advance.
Proposition 8, an amendment to the California Constitution, provides that "only marriage between a man and a woman is recognized or valid in California."