Homer- Republican, though an very apethetic one
Marge-Democrat
Moe-Democrat, being a first generation immigrant
Skinner-Democrat. Too afriad to make a choice, but Edna convinces him and he has to kow tow to the teacher unions
Comic Book Guy-Republican, small business owner
Otto-Democrat, he'd want to stick it to the man
Flanders-very Republican, part of religous right
Apu-Republican, also small business owner and first genreation Indians are usually GOP
Mrs. Krabaple-Democrat, for obvious reasons
Lenny-Republican because he disagrees with Carl
Carl-Democrat because he disagrees with Lenny
Lionel Hutz-Democrat, because he's with the ambulance chasers
Grandpa-Democrat, because he's pissed with Bush's Social Security plan
Cletus-Republican, because his hillbilly constituency
Keep in mind, these are vast generalizations.
All agree, except you find that people who own businesses dealing with entertainment usually vote Democratic or Green, and Hindus just don't vote Repub.