How do we make sure elections are not stolen? Prove you are eligible. Then why not dip one's thumb in a bottle of dark blue ink? No thumb. No vote. Dark Blue thumb means you voted already. The first eliminates the dead, the illegals and the felons. The second eliminates the repeat voters.
If this is acceptable we need to move on to the people who count the votes. They are the ones who determine the vote's outcome and that is where the real voter fraud occurs (in my opinion).
Perhaps this is one place where we need chain gangs and breaking rocks in the hot sun for twelve hours a day as punishment for voter fraud. Plus, for good measure confiscate the guilty party's property, auction it off. Then give the proceeds to the other political party.