Yes, getting hard data on voter purges is difficult; it's not like they are centrally reported. And, it happens over years and is distributed unevenly over pre

Yes, getting hard data on voter purges is difficult; it's not like they are centrally reported. And, it happens over years and is distributed unevenly over precincts. And, when it is of questionable legitimacy, they work to hide it. The data on precinct-by-precinct voter roll delta vs margin of victory that you mentioned would indeed be very revealing.