Disenfranchisement - or just fraud prevention?
This one is pretty cut and dried to me: anyone who votes ought to be able to prove they are eligible. The only people who are going to get left out are those not on food stamps, don't have a drivers' license, don't ever fly anywhere, don't drink alcohol, etc. It prevents vote manipulation by groups like ACORN.
I know this is very tricky and it can lead to people in power using voting rules to stay in power. But if it were done right, I'd be okay with a very basic test to vote to be sure you know something about the candidates you're voting for. Maybe it's too dangerous, but there's something appealing about getting people who've hardly heard of the candidates they're voting for from voting.
Another thought is that in order to vote, you have to take a short questionnaire to test your knowledge: like who the candidates actually are (makes voters actually do their homework - at least a little).
In Heinlein's "Starship Troopers", he made a case for public service in the military as a pre-requisite for voting.
Personally, I think one of the things that would improve voter education is to drop the law that prevents politics from being preached from the pulpit. In the founding days of our nation, that was the most common way for people to learn about the policies of the government - both local and national. But to do that we'd have to change the election and taxation laws.
That's my favorite. I don't want to keep certain people political groups from voting. I just like the idea of it being a little bit hard to vote.