Through my career I have a pretty good eyes for spotting how something can be gamed. It is real easy to game a polling place. First, they use volunteers, some that are not up to the task but they volunteered to why not allow them to work the poll. This leads to even the procedures in place not being followed. Add to that people that are real clever at the polling stations are no match.
For starters, poll workers should be county employees properly trained, not volunteers paid for the day. That would be the first big necessary step.
Our local polling places for years, have used voting machines. A person coming in from outside couldn’t do anything to them but a dishonest person who set up the machines sure could.