If the general election is Feinstein vs de Leon, that would be amazing. However, to really get the benefit of depressed Republican turnout, the Governor's race needs to be DvD as well, or maybe at least Democrat vs Ultimate "Some Dude," although I'm not sure how bad that would be for the CAGOP in terms of turnout.
While not as interesting, I'd also note that Republican state legislative candidates in California would be in trouble if no Republican made it to the GE in CA's Senate/Governors races. They rely on ticket splitting and optimal Republican turnout to stay afloat in Romney/Clinton or Obama/Clinton districts. If they see lower turnout and more straight ticket voting in 2018, Democrats could really sweep legislative races and build a comfortable supermajority.
You beat me to it. The prospect of having both the Governor's race and the Senate race be D vs. D is highly problematic to down-ballot Republicans. And when I say highly problematic, I really mean catastrophic. Securing the supermajorities is just the beginning. If 5-7+ Congressional Republicans are facing defeat, Nancy Pelosi will easily be Speaker once again.
