A microwave jammer at each of the 100,000 or so polling places would neutralize this threat. And they would only been needed at a fraction of that total - just the large population areas in blue-controlled cities. It might cost $100 million but if it eliminated election rigging, wouldn’t it be worth it?
Send poll watchers in to make sure there are no hardwired connections as well. Pull the plug and jam the airwaves!
I had that idea several years ago. I’m sure patriots across the country would donate big $$$ to make this happen!