The State Supreme Court upheld the ban in May, but the timing of the federal case has some advocates for same-sex marriage arguing that a failure there could damage their efforts to persuade voters to reject the proposition.
Such views have discouraged longtime gay activists, who have watched several states legalize same-sex marriage recently.
“The troops, such as they are, are more disunited than ever and battling each other to the next failure,” said Larry Kramer, the playwright and a founder of the group Act Up, which led the fight for AIDS research. “They cannot agree on anything now.”
Officials with Equality California and the Courage Campaign said that was untrue.
“We’re all in this for the same thing,” Mr. Jacobs said. “I don’t see why this should put us at cross-purposes.”