OK...Voter Id requirement I can go along with. If I misread what you said before then I am sorry. I am pretty tired. I just don't like the talk I have heard before about Getting National ID cards.
Just require all federal elections to have social security numbers used to check in registered voters and all voter lists to be electronic. Voters without social security numbers but are citizens can vote provisionally.
This would eliminate all dual voting, voting in two states, and so on. Would be easy to implement.