A lawyer for two couples challenging California's gay marriage ban told a federal judge in San Francisco Friday that two rulings by another U.S. judge in Boston Thursday provide "compelling support" for their case.
Walker is presiding over a nonjury trial in which two gay and lesbian couples claim Proposition 8, California's voter-approved ban on same-sex marriage, violates their federal constitutional rights.
Walker conducted the trial in January, heard closing arguments last month, and is currently considering a decision. He has not indicated when he will rule.
Olson wrote in the letter that U.S. District Judge Joseph Tauro of Boston "considered and rejected many of the same irrational justifications asserted by proponents in defense of Proposition 8."
The rulings show that "none of the unfounded rationales asserted by proponents in justification of Proposition 8 can sustain this discriminatory law," Olson argued.
Tauro's decisions struck down a provision of the 1996 federal Defense of Marriage Act that denied federal benefits to same-sex married couples.
He ruled that the law violated legally married gay and lesbian couples' constitutional right to equal treatment. Massachusetts is one of five states that allow same-sex marriage.
A spokeswoman for the proponents of Proposition 8 and their campaign committee, ProtectMarriage.com, was not immediately available for comment on Olson's letter.
Their lawyers have argued that state voters had a rational basis for believing that heterosexual marriage promotes "naturally procreative relationships between men and women to provide for the nurture and upbringing of the next generation."
Proposition 8 attorney Charles Cooper argued at the close of the trial that the purpose of marriage is procreation and said that definition is "fundamental to the very existence and survival of the human race."
The trial has been the nation's first federal trial on a challenge under the U.S. Constitution to a state law banning gay and lesbian marriage.