At this point whether republicans fuck up depends on whether the gop candidate will fight the fraud or not. Virginia was won by having more vigilant poll watchers, New Jersey was lost by refusing to contest the ballot stuffing.

I suspect the vast majority of Democrats rely on cheating to get their seats. 2018 was the first extremely widespread case where they blatantly kept finding more ballots until they won, though they've clearly been doing that on a smaller scale since Al Franken.