They should actually purge the voter rolls every year, and make every voter re-register to vote for every election.

This will ensure that all of the various scenarions that occur wont create opportunity for cheating.

For example, if someone lives somewhere, and registers to vote, and then moves somewhere else, and also registers to vote, they are still “registered” to vote in the first place,

and just because they move away, doesnt cancel their voter registration at the first place, so someone could in theory cast a vote using their name, without their knowledge

By purging the entire voter registration roll after every election, you ensure all of these obsolete voter registrations are purged from the rolls in a timely fashion.