Dems in California are dropping out:

"By Wednesday, a handful of Democrats had abandoned their campaigns to replace retiring Republican Reps. Darrell Issa and Ed Royce in Southern California. But as the candidate filing period closed, the glut of Democrats remaining still threatened to split the primary vote — leaving open the possibility that two Republicans could advance to the general election, wiping Democrats off the ballot entirely in November."

https:// www.politico.com/story/2018/03/15/california-democrats-disaster-2018-ballot-465460?cid=apn