So political donations are often open even small donations you can use that and social media to find the majority of magas in the state. One of the most obvious disqualifying criteria is voting in another state or being dead names being pretty non-unique you can find someone who died or votes in another state with the same name for most people. If you automate this you can probably legally file a challenge for literally every Trump voter in your county.

If you make this automation available you can probably with a little help from your friends (thank you joe cocker) file a challenge for every Trump voter in the entire state.

I'm betting this wouldn't actually disenfranchise anyone though because the system would simply collapse under hundreds of thousands of challenges.