Can you imagine what kind of devious behavior would go into writing, wording, producing, and administering that quiz...
Our elections are bad enough with the electoral college, super delegates, and gerrymandering.
Interesting that you assert "Our" in the sense of the US.
Then don't invalidate that vote, print off the exam for the voter with their score, still let the voter vote. Maybe you get multiple 'I voted' stickers if you pass the exam with flying colors.