For Obama, you could set up a Chicago-style hot dog bar (just don't supply ketchup if there's a real Chicagoan in the room; trust me). The ingredients are pretty easy to source, and this way, guests can customize their food. If you don't want to supply a whole meal, try making a quick and easy Chicago snack — maybe your own caramel corn as a riff on the ever-popular Garrett's Corn.
For Romney, you could prepare New England Clam Chowder (or Fish Chowder, if the clams aren't readily accessible). If you want something a bit sweeter, you could opt for a cranberry dessert, since the cranberry is Massachusetts' state fruit, or you could try your hand at a no-bake Boston Cream Pie or Boston Cream Cupcakes.
If you want to represent libertarian candidate Gary Johnson, go for southwestern fare, perhaps Mexican chicken soup, easy slow-cooker carnitas (start these as soon as you decide to host!), or a simple dish of guacamole as a snack.
As for me, I'll be choosing an array of good American craft beers. I'm fortunate enough to live down the street from Revolution Brewing, so I know where my election-night loyalties will lie, but there are a lot of great options out there.
Activities: I've never been that into party games, but on election night, I really like keeping track as the votes come in. It could be fun to make a few print-outs of these maps, pick up some dollar-store crayon sets, and fill in the reds and blues as they are reported.
Music: If all the commentary gets to be overwhelming, you could mute the TV and stay in the mood with some Americana tunes. I put this music mix together for 4th of July, but I think it works just as well in this context.
Do you have any other ideas or suggestions for a last-minute get-together?