In small measure and ineffectively. You can’t stop much before it happens and once the vote is done and “counted” and the winner declared it does not matter what fraud is proved. The declared total will stand. Only local elections have ever been overturned for fraud and extremely rarely. All the fraud proven and the Democrat operatives that have gone to jail since the last election did not get any precinct revoted.
The organization I belong has a bit of success, but you have to keep on the state/county/local area’s behind and BIGTIME.
It needs to be too lopsided to cheat. I pray that Trump plays this well and not tone-deafly, not letting himself get baited into looking the kook.