Racism/sexism, shitty Democrat messaging, misinformation, shit like that made a tight race go towards Trump... but the reason it wasn't a wash was because millions upon millions of Americans decided it would be better to not show up and leave the fate of their country in the hands of others than make any kind of meaningful decision.
There was election fraud, but in my opinion not to the extent that it had a significant effect on the outcome. Particularly things like the burning of several ballot boxes, bomb threats, etc. One thing we know about republicans is that they love to accuse people of things that theyre guilty of.