So it was obvious that Trump was going to lose the election to Biden. So Russians manufactured one of the most ridiculous stories in history. They claimed Hunter Biden had a laptop full of incriminating documents and videos, so he flew across the country and left his laptop with a blind computer repairman. Then he promptly forgot about the laptop and left it at the shop for years. Then the blind repairman did what any blind computer repairman would do in a bad spy novel: he hacked into the files and read all of Hunter Biden’s personal information.
So the fake laptop and fake files were turned over to the FBI, but since that agency isn’t staffed exclusively by morons, they realized this was a Russian disinformation campaign that would only fool the stupidest people in the country. So the Russians fed the story to one of the stupidest people they could find, Rudy Giuliani, who seems to have been dumb enough to believe it. Fortunately for the Russians, the people they were hoping to fool were in fact the dumbest people in the country, so the story got some traction on Fox News, alt-right radio, and presumably in Klan meetings.
All the reasonably sane people with IQ’s above 70 figured out it was nonsense, while the rest still believe it had to be true because they saw a press conference about it at a lawn and garden store (okay, technically that press conference was about an even dumber conspiracy theory about the election being stolen, but it targeted the same morons, and they probably don’t remember which was which because all they care about is “Biden is Satan and Trump is Jesus”.)