Walker heard more than 90 minutes of arguments Tuesday and said he would issue a written ruling later.

Three groups that opposed Proposition 8 are challenging U.S. Magistrate Joseph Spero's order earlier this month requiring them to hand over all documents "that contain, refer or relate to arguments for or against Proposition 8," with the exception of private communications between their core leaders.

At Tuesday's hearing, lawyers for those groups contended the disputed e-mails and memos were irrelevant to the case, and it was unfair to make the groups sift through tens of thousands of documents because they were not officially part of the litigation.