What if people don't want either choice? Perhaps they are weirdos like robroy and view all the politicians as rapists since they represent the forced tax apparatus of the state, or whatever. You going to force people to back a rapist?
We have a lot of dumb people. I go the opposite direction, and yes it's got horrible historic context, but i think you should have to take a test to demonstrate a basic middle school level understanding of government. You should know as much as a 5th grader in order to vote.
You know how you say America is in decline...well...its our own fault. We hate informed decision making and we hate taking responsibility for our ill informed decisions.