It’s not common knowledge but there is no legal requirement for either party to run democratic primary elections. They used to just pick candidates with no public input. They opened up voting as a concession to their supporters. However, they did so in a way that allows party officials to tip the scales in their favor.

The cruel irony is that the democrats actually have a less democratic primary than republicans simply because their voters interests are not aligned with the interests of party officials. Of course republicans party officials don’t care about democracy either but neither do their voters.