I was just watching Starship Troopers again today. I like that movie for a lot of reasons, not the least of which is its idea that citizenship isn't conferred by birth.
Talking about the Virginia's governor's race and voting, I said, "I feel it's better to make no decision than an uninformed decision". I really don't think that all people should have the right to vote. Some people are just stupid. Some are just ignorant. I thought that maybe some kind of test to evaluate a person's knowledge prior to allowing the person to vote might be good (on an at least yearly basis), but I think the test writers would then have a lot of political sway.
The idea in Starship Troopers that you have to earn citizenship is an interesting one though. I suppose the idea is that if you care enough about your country to do something for it, then it shows that you should have a say in that country's government. I haven't read the book, though, so I don't really know anymore than that.
The bottomline is, I think people, in general, are stupid. In America, it seems like we have more than our fair share of stupid people. And sometimes even a minority of stupid people can move the country towards more stupidity.
Whether it's through testing or some kind of public service requirement (or whatever), there really does seem to be a need to weed out those that would do harm to the country.