What did we do 4 and 8 years ago when we thought we were getting screwed. Keep data, get proof that these numbers are what they say they are.
This is a close election, not a landslide, but these aren't particularly close races. It's not a handful of votes.
And if they want to do shenanigans, the people know, really, who is capable of it. The GOP organization might have the same kind of cheating capabilities as the Dems do. There really isn't any evidence of that, but it's the political parties who have that ability. Not Trump, and the GOP isn't going to be breaking all sorts of rules to help Trump.