WASHINGTON - Some election-year advice to Republicans from a high-ranking source who has the president's ear: Don't use a proposed constitutional amendment against gay marriage as a campaign tool. Just who is that political strategist? Laura Bush. The first lady told "Fox News Sunday" that she thinks the American people want a debate on the issue. But, she said, "I don't think it should be used as a campaign tool, obviously." "It requires a lot of sensitivity to just talk about the issue — a lot of sensitivity," she said. The Senate will debate legislation that would have the Constitution...