California's ban on gay marriage goes to trial on Monday in a federal case that plaintiffs hope to take all the way to the U.S. Supreme Court and overturn bans throughout the nation. Victory for gay rights groups in the Supreme Court, which might not choose to take the case if it is appealed that far, would make marriage a fundamental constitutional right without exception and overturn laws and state amendments limiting marriage to a man and a woman in 40 states.

Source: http://www.reuters.com/article/idUSTRE60A0OP20100111