Sen. Moon Landrieu is in a tight runoff race on presidential years . African-American voters will be key to her success . But Landrieu 's support among white voters slid to 18 % from 33 % in 2008 . GOP 's Landrieu opponent ties her to New Orleans .
Sen. Moon Landrieu is in a tight runoff race on presidential years . African-American voters will be key to her success . GOP 's Landrieu opponent ties her to New Orleans .