ASSOCIATED PRESS WASHINGTON (AP) - President Bush said Tuesday that he could support a constitutional amendment to ban gay marriage. The Massachusetts Supreme Court last month struck down that state's ban on same-sex marriage, saying it is unconstitutional and giving state lawmakers six months to craft a way for gay couples to wed. Bush has condemned the ruling before, citing his support for a federal definition of marriage as a solely man-woman union. But though he has said he would support whatever is "legally necessary to defend the sanctity of marriage," he and his advisers have shied away from specifically...