A measure to repeal Proposition 8, the anti-gay marriage initiative, has failed to qualify for the November ballot.
John Henning, who heads a group that sponsored the repeal effort, declined to say how many signatures had been gathered since the all-volunteer campaign got underway in late November. He said 694,000 valid signatures were required by Monday.
"There comes a point where the intake of signatures isn't rapid enough to make up your deficit," Henning said. "We started to realize last week that we weren't going to make it."
He said his group, Love Honor Cherish, will work with other activists to put a repeal measure on the November 2012 ballot.
The effort to repeal Proposition 8 this year relied heavily on the Internet. Supporters could download signature-gathering forms and watch videos about how to approach voters.
Henning said he did not regret the effort, despite its failure.
"We have kept this issue in the public's eye for the better part of a year, and the signature-gathering in itself was a huge opportunity to talk to the public," he said.
A constitutional challenge of Proposition 8 is pending in a federal court in San Francisco. Closing arguments in the case, expected last month, have been delayed because of disputes over the production of documents sought by proponents of the initiative.
Even if the federal challenge succeeds in the lower courts, a repeal measure should be placed on the 2012 ballot, Henning said.
"We have a conservative U.S. Supreme Court, and it is going to be very hard to win that case in the Supreme Court," he said.