In reply to:
Libertarian objections aside, the people who wouldn't feel inclined to vote if they didn't have to would probably just vote for any old candidate without giving much thought to it. Though, that's probably what most people do anyway.
Not so. I think the way the media portrays political parties and leaders has a lot to do with it. If the media supports a government, it's going to be harder to displace it than if it supports an opposition party - and how undemocratic is that?
Just think of it as sampling. The larger the sample size, the more accurate the resulting representation; however, even a 100% participation rate will yield some margin of error.
Give Me A Break