It cannot be defeated with poll watchers. I am not suggesting we stop this. But it is not news that poll watchers report fraud and nothing is done.
First thing is to get voter ID. It will be a battle. Even states that have voted for it have been stymied by the courts.
The first thing is to end voting for weeks leading up to an election.
I read that the UN inspectors were surprised that no photo IDs were required
Best poll watchers? High school seniors. No one knows who they are till a week before election day. They are randomly selected from across the country and none of them work in the district they live in.