As this anonymous source said, the example of Seth Rich is clearly embedded in their memories. The Democrats don't handle malcontents in the same way Republicans do. There are basically no repercussions for people who bash President Trump anonymous or not. The Democrats are lawless and feel entitled to kill whoever releases info that they consider damaging.
The difference being, Rich never got to complete his task. No doubt the dems know who this anonymous source is; if it’s true, he may as well make a clean breast of it.