If Obama is the nominee, I expect that Democrats wil do better across the board in congressional races.
I think he helps Democratic candidates in the South and midwestern cities by boosting the black vote, particularly affecting:
MS-Sen, NC-Sen
LA-05, LA-04, MS-01, AL-02, OH-01, OH12 (possible sleeper upset), OH-15, NC-08, VA-02, VA-05, etc.
Of course the IL coattails may push IL-10 over the top and may even spark an IL-06 upset.
He could definitely help in AL-3 which is about 33% black. If the Democrats had a serious candidate there they might reduce Mike Rogers' usual 60%-39% margin.
