Jungle Primary?
Never heard of that before, I must admit!
Sounds racist to me.
Here’s a pretty good link to the specific California House races that the dems are worried about.
https://www.ocregister.com/2018/03/15/republicans-start-to-wise-up-will-democrats-follow/
Louisiana has used this kind of primary since 1975. I think Washington State is now using it too.