Hey, we can make this really simple, and follow the example of a great many other nations.
First, everybody gets a special internal passport.
Then we mandate voting at all elections. And when you vote, you get a stamp in your passport. Fail to vote, go to jail.
There we go, perfect democracy!
Then we can even take it a step further! When they stamp your passport, we can put in it what party you vote for! Hey, this would be perfect!
That way when some pig-dog Republican (and you know they all hate Welfare) tries to apply for some kinf of Federal program like Food Stamps, we can just kick them out, denying them since obviously they are against such programs in the first place.
There, perfect solution to all the problems. Perfect Democracy, where nobody is denied the right to vote.