Most Democrat Super-Delegates hold an elected position and therefore were elected by the public. The public just never realized some elected position’s included a seat in the Democrat Presidential Convention Politburo. In a sense, even Republicans and Independents had a say in seating the Super-Delegates.
Well, at least now, every Dem Congressman and Dem Senator gets a superdelegate slot — back in ‘84, only certain ones did — so far as I could figure, it was the ones that supported Mondale, with a few token others...