Also, the purpose of Republican voter purges is not, particularly, to find people who have double-registered. It is more useful to the GOP to have a ton of fals

Also, the purpose of Republican voter purges is not, particularly, to find people who have double-registered. It is more useful to the GOP to have a ton of false positives. Having a huge headline number allows them to claim that voter fraud is rampant ("Over a million people double registered!!!"). It also allows them to challenge the registration of many voters that the GOP doesn't like. Whether they've actually succeeded or not in finding double registration, these challenges raise the bar of voting difficulty for the other side.