This probably wouldn't be a great idea. Most people who wouldn't have voted anyway don't care about politics and would put absolutely no effort into researching candidates and making a wise decision. The people that vote now at least attempt to make a decision (even if they're voting strictly by party, if that's what they think is best at least they have an opinion). If everyone had to vote it would turn into even more of a popularity/name-recognition contest than it is now, because the uneducated (on the candidates) voters would simply pick the first name they recognize.
Then again, if the fine is only about $20, a lot of people would pay it just to get out of the "hassle" of voting. Increased revenue isn't a bad thing
