We would need a database of all voters with facial image detection to show real-time repeat voting of individuals linked with watchers in every precinct in every state.
You would still have to have a Board of Elections that wants to stop fraud. I suspect most don't so it wouldn't matter what you did to count or identify fraudulent voters.
You don’t understand how democrats cheat. When democrats cheat they vote the people who don’t bother to show up. Here’s how easy it is to catch. If 200 people walk into a precinct to vote - and at the end of the night the vote shows a total of 3,000 people voting - there’s fraud. You don’t need fancy cameras. The old fashion kind will do just fine...