John Podesta’s email leaks lays it out in detail for one of the elections (2016). Hillary did the best she could to spin the leaks trying to discredit the source (blaming Russia and WikiLeaks) rather than talking about the actual content of the leaks.
In 2020, the DNC heavilly convinced all the establishment candidates other than Biden to drop out right before Super Tuesday in a cordinated effort while making sure Elizibeth Warren stayed in the race to ensure that Bernie had as small of a chance as possible of winning, since he was winning big-time until then, not to mention the news-media falsely calling one of the elections for Mayor Pete when Bernie won that race.
In 2024, the DNC did all they could to hide the fact that there was even a primary at all, working with the news-media to ensure that they didn’t even mention the competing candidates.