You know, Yknot, Bernie himself does not believe those claims. (Yeah, he claimed there was some bias, some railroading, but he stopped short of actual accusations of fraud, which is a crime. Certainly not to the extent Republicans have in their rather hopeless crusade to paint Hillary as a liar while their candidate tells obvious and absurd untruths.)
Like I said, they have trouble seeing reality. The "scandal" around Vince Foster (I use the term loosely) makes little sense, seeing as the police, coroner, FBI, Ken Starr himself, and even Vince's family all insist he shot himself with the gun that was in his hand and recently fired when his body was found. Nonetheless, the Trump supporters insist again and again he was murdered, ignoring every expert and ignoring reality.
Occum's Razor, Yknot.