We watch citizens overthrow governments and assume the same thing couldn't happen here. But we have had one big civil war in the U.S., and several states -- including California, where I live -- have been talking about getting out of the U.S. for decades. What appears to keep us together isn't the political structure; I think you could argue the USSR's was actually stronger, and it fell. It is the appearance that the government is representative. What if a majority, or even a massive minority, believed it wasn't -- much like what happened in the Civil War?