I’ve a lot of discourse online about how the Democratic Party held back Bernie Sanders from becoming president in 2016 & 2020 during the primaries. But my question to that is, are primaries not decided by the voters to get the most delegates? If the people didn’t vote for him, how is that the Dems’ fault?

A counter I see for that is that Dems endorsed his primary opponent to sway the vote. I dont really think that would have much impact on committed voters. Trump got almost no help in the primaries in 2016 and still won.

Is this narrative true and I’m just oblivious?