The sponsors of California's same-sex marriage ban said Monday that the recent disclosure by the federal judge who struck down Proposition 8 that he is in a long-term relationship with another man has given them new grounds to have his historic ruling overturned. Lawyers for the ban's backers filed a motion in San Francisco's U.S. District Court, arguing that Chief U.S. District Judge Vaughn Walker should have removed himself from the case or at least disclosed his relationship status because his "impartiality might reasonably be questioned."