There's a simple solution to this:
1) Mandated voting for every citizen over the age of 18, or pay a fine, lose your driver's license, whatever. Something that's too painful to avoid voting.
2) Create a national voter's "holiday" that must be respected by ALL business, or they pay a fine large enough to discourage playing loose on the rules.
Too bad that will never, ever happen.
It'd be nice for everyone to vote, but this is America and people should have the right not to vote if they don't want to. I remember hear about some country that everyone had to vote (Serbia maybe).