Don't you already have to show an ID? When I voted in STL and Lexington Kentucky we had to. But that doesn't stop someone from voting twice.
In CF you are PROHIBITED from asking for ID.
Not in WI.
In Maryland, poll workers are instructed that they may not ask for ID. It might hurt someone's feelings. That's how so many are able to vote in more than one precinct. A person can move, even within a county, vote at their old and new address. Who's checking? We even have dead people voting.