Independent news source Politifact has rated the claims made by Sanders’ supporters about how Nevada Democratic Party leaders "hijacked the process on the floor" of the state convention "ignoring the regular procedure and ramming through what they wanted to do”, as articulated by campaign manager Jeff Weaver, as blatantly false.
Some of the key points:
There were no last minute rule changes sprung on convention-goers — the rules had been publicly available weeks in advance, largely unchanged for three presidential cycles, and given to both campaigns.
Although several videos from the event appear to have louder "nays" than "yays," both preliminary and final delegate counts showed that Clinton supporters outnumbered Sanders supporters in the room.
The Sanders campaign later alleged that Lange refused to accept petitions to change the rules, which is inaccurate.
Magnus said the committee spent much of Saturday investigating the delegates called into question, and eventually seated six of them. The remaining 58 delegates were rejected because they were either not Democrats by May 1 or the party could not confirm their name or address.
Importantly, the state party reported only eight of the rejected delegates even showed up to the convention, so even if they had been seated it would not have flipped the majority. "It didn't affect the outcome in any way," Magnus said.
From all this, Politifact concludes:
The howls of unfairness and corruption by the Sanders campaign during Nevada’s state Democratic Convention can’t change the simple fact that Clinton’s supporters simply turned out in larger numbers and helped her solidify her delegate lead in Nevada.
There’s no clear evidence the state party "hijacked" the process or ignored "regular procedure."
So there you have it folks. This is what all the seething uproar was about. Absolutely nothing other than their petulant anger and irrational behavior boiling over into a wailing tantrum over not getting the outcome they wanted.
Politifact Article