So, while everybody goes bonkers over super-delegates:

https://fivethirtyeight.com/features/are-democrats-courting-chaos-in-2020-by-limiting-the-power-of-superdelegates/

https://www.theguardian.com/us-news/2016/apr/19/democratic-party-superdelegates-history-rules-changes

https://fivethirtyeight.com/features/the-system-isnt-rigged-against-sanders/