The trouble with all three of these is that it has to be done systematically across all polling places across a diverse number of counties -- or you end up with

The trouble with all three of these is that it has to be done systematically across all polling places across a diverse number of counties -- or you end up with this: https://www.nytimes.com/2018/12/07/upshot/mapped-why-voting-anomalies-are-impossible-to-ignore-in-north-carolina.html https://www.nytimes.com/2018/12/07/upshot/mapped-why-voting-... (Although they admit that it would be easier to do in some states than others.)