we have a perfectly functional system for overthrowing the government on a periodic basis: voting.
That is probably the funniest thing I've seen posted here for a long time. Our election system is broken. In our system, two major sources of power (ie, the political parties) pick a handful of candidates and let the people fight about which one of the pre-chosen people they want to be in power.
Furthermore, the winner is decided in part by the people, but there is a LOT of money that gets spent in elections and the more money you can spend, the more likely you are to win. Right now, the only practical political choices boil down to either a Republican or Democrat, both of which are run by a small group of elite. This is why we have things like the Bush dynasty - do you really believe that father and son were both president because of their merits and not their wealth and influence? Hell, on the other side of the coin, we almost had a Clinton dynasty starting when Hillary was showing real potential to take the oval office.
If that's not enough to start you questioning our "perfectly functional" system, I would suggest you read all of the articles posted on slashdot about the trouble with the voting machines used in most elections!
To change this, we first need enough people in the streets to generate enough political capital for someone to step up and try to represent these new voices. Even if that doesn't work, they are already having an effect. Without them being on streets, we wouldn't even be having this conversation, and the longer they stay on the streets, the more people will talk about why they are there and these ideas will start to spread.
My only hope is that this kind of movement can generate enough momentum to actually cause a change.