Does this whole discussion not reflect how backward and Hill Billy the US really is in many regards, including this issue?
Most every developed country actively maintains and manages residential information on a council/county/town level. Those registries reconcile with national registries as well as censuses are carried out every now and then.
Now, during each election a voter's ID is checked against the local registry and such voter can vote once and only once.
Nobody in the rest of the world even starts to understand why this is not being done in the US. Aside a few multi standard deviation out edge cases (aka statistical errors) no dead, illegal, or non eligible voter should ever be able to cast a vote.
So, care to explain to the rest of us non Americans, how this can even happen unless those stories are all made up and outright lies?