I suspect it wasn't lack of voter fraud, but Democrats believing their own propaganda and assuming Hillary had a landslide victory coming... and deciding this was a good reason not to vote. I think this is what happens when Democrats believe they no longer have to make the victory happen.
It's a combination of factors. Blue collar northern workers came home to their true party and the Blue Wall came tumblin' down. This is not an anomaly. The leftist policies have been handed a thorough rejection.