I'm not sure if he runs unopposed, or if there is a token GOP opponent, but everything I've read says that the winner of the Dem primary will win the November election.
I think he's got himself in a mess, and is hoping something happens to get him out of it.
FYI to all on this thread: Here's a summary of one of the problems with the DA's case (from another FR thread)
Meant to add that the post is #1591