There is an interesting article in The New Yorker available online about political knowledge (or lack thereof) and why it is perhaps not a bad idea that many people do not vote. There's little need for me to repeat the article, which is really a book review, except to paraphrase an old Mark Twain line about half the people don't read a newspaper and half the people don't vote and how he hopes it is the same half.
If you have any interest in what people know, voting, and the intersection of the two, take the time to read the article and even (gasp!) the book it discusses. When I get a chance to read the book I'll post my thoughts here. At the moment I'm finishing another (The Cult of the Amateur: How Today's Internet is Killing our Culture). When done, I'll touch on that one first. Some fascinating stuff.