Homer Simpson - Wait, so there's another Homer Simpson on the show?
Romney, as the clip showed.
Marge Simpson - She's stated that she voted for Carter twice, and is a big supporter of the Democratic Governor of the state that Springfield is in. So Obama.
Bart Simpson - Rebellious and sometimes a conspiracy theorist. Either Gary Johnson or Jeff Boss.
Lisa Simpson - Staunch environmentalist, gay rights activist and pacifistic. Probably Jill Stein.
Maggie Simpson - Very fond of guns, it seems. Virgil Goode?
Grandpa Simpson - Has bashed the Democrats numerous times on the show. Romney.
Nelson - Johnson
Comic book guy - Johnson
Ned Flanders - Write-in: Bachmann
Todd Flanders - Him and his brother are strongly implied to be gay in a futuristic episode. Probably Obama.
Rod Flanders - See above.
Chief Wiggum - Romney
Ralph Wiggum - Boss
Monty Burns - Romney (most obvious one yet!).
Mr. Smithers - Would tell Mr. Burns that he's a Romney supporter, but would in fact vote for Obama.
Fat Tony - Romney
Snake - Johnson
Hans Moleman - Always needs healthcare. Obama.
Duffman - Romney
Dr. Nick Riveria - Johnson
Edna Krabappel - Obama
Lionel Hutz - Romney
Professor Frink - Obama
Mayor Joe Quimby - Obama (he's a Democrat).
Captain Horatio McCallister - Romney
Patty - Obama (she's a lesbian).
Selma - Romney (because he's the best looking candidate).
Otto Mann - Johnson
Cletus the Slack-Jawed Yokel - Romney
Lenny - Obama
Carl - Obama
Barney - Obama
Moe - Obama
Willie - Obama (he's Scottish).
Superintendent Chalmers - Romney
Principle Skinner - Romney
Apu - Obama
Milhouse - Johnson
Krusty the Clown - Romney