LEWISTON, Maine (AP) — In the whitest U.S. state, thousands of miles from the Mexican border, the debate over immigration is quickly becoming a central issue in one of the nation's most closely watched governor's races. There's not an endless pot of money up there. Since January, more than 30,000 children, mostly from El Salvador, Honduras and Guatemala have crossed the nation's southern border illegally and have been placed with sponsors throughout the country. In Connecticut, Democratic Gov.