NEW ORLEANS (AP) — Who is Ray Nagin? Is he the man New Orleanians believed they were electing mayor four years ago? The corporate executive with an MBA who wooed voters with his quick smile and promises of a more prosperous future? Or is he the man on the radio after Hurricane Katrina, the one who melted down in a ranting tirade against state and federal officials? Is he a racist, someone willing to exploit the uncomfortable black-and-white divide to win re-election with a "chocolate New Orleans?" Or is he the larger-than-life character calling for unity on billboards in the...