Imbro - an interesting point bringing up "Poll Tax." An associate and I have come up with a substantially similar solution, with different mechanics...
When entering the polling place, the voter must pay a "tax deposit" of, say, $100. After making the deposit, the voter is given a question designed to test his intellect - be it in maths (to Algebra/Trig,) History, Philosophy, General Science, or whatever. Something a High School graduate would be able to answer - but that his dog could not.
Answer the question correctly, you get yout deposit back and you get to vote. Fail, and the machine keeps your deposit, and flashing red lights go off. Protest on form I-D-Ten-T.
Of course, the question and the ballot are both in American English ONLY!
This could serve two purposes -
1) Generating a sliding windfall for the government around taxtime. Put the "ballot take" into a special fund for use on special projects, or an emergency fund for a "rainy day."
2) Make some progress toward ensuring a certain level of mental competence for our electorate, as well as a useful language skill (last time I checked, all the major rags are in English.) Of course, the voter would be allowed to pick his subject from a pool made available to the machine. And, only the machine and the programmer pool would have access to the answer pool! Presentation of an occupational certification of competence in a mathematical or scietific subject form a practical viewpoint (city engineer, surveyor, or somesuch) would allow the voter to waive the requirement for the Question.
FFZ