The Sierras have a lot of Mormons. Mittens should win there. Rick should take the Central Valley, but I question whether he will win anything in the inland empire. California is kind of light on down scale whites these days. Most have left the state.
Rick wins SBD county if he can hold Romney to below a 10 point margin I think. Yes, he will lose Rancho and Chino Hills, perhaps Redlands as well, but I don't see him doing well almost anywhere else. How do you think Yucaipa will vote? Not for Romney. Also, in that Pomona to SBD corridor there might not be a lot of whites, but the ones who live there tend to vote Republican and not the type who will be fond of Romney. In Riverside, CA-41 and 42 will be two districts that might vote for Rick. Another question might be how the few Hispanics who vote will swing. They could affect a CD or two. The new 46th in OC could be one such district.
Yes, I understand about the class thing in CA-41, and CA-35 (antelope valley and clarita hills and simi valley), and the Riverside CD, but how Evangelical are those folks, which has been a key variable? Mittens does OK with downmarket whites if not Evangelical. And these folks are not that down market, just lower middle class. I don't think many Hispanics will be voting. How many are even registered Republicans? Also bear in mind that a lot of old whites are in those CD's, as a cheap retirement, or because they are too poor to retire elsewhere, or whatever. Mittens does well with olds - even poorer ones.
One thing I do know. Rick won't be carrying my CD. 
That was my thinking anyway, when I considered the issue of who had the edge in the CD's that you mention.
The Simi Valley to Antelope Valley CD may just vote for Romney actually. Looking at the CD's, I don't see many more than say 8-10 that are locks for Santorum. Of course it's unlikely he gets within 10 points even if he is running alone against Romney. Even worse if Gingrich is still in there splitting things up.
Here are the CD's I think Rick can win or get close in if he is the only ABR left (ignoring Paul of course).
CA-2 might vote for Rick. It's a little more Mormon than the state (but the main population centers aren't really more than about 2-3% Mormon, the main Mormon concentration in a big county is Placer) but it is also fairly socially conservative and not that wealthy. Should be a close one.
CA-3 will probably vote for Rick. Many of it's Republicans will be located in rural areas and around Yuba City/Marysville. Doesn't strike me as Romney country. Also the whites in Vacaville and Fairfield tend to be pretty downscale.
In the central valley, CA-9,10,16,21,22 and 23 should vote for Rick. The 9th could vote for Romney though and the 10th and the 22nd should be close.
Moving to Socal, the 8th is likely Santorum country. The 35th and the 41st as well as I have mentioned. The 42nd (Corona to Murrieta) should be very close. Also CA-50 in SD will be another one to look out for. So basically about 12 districts Rick is favored in or about even while losing by 10. Some of those Latino districts could be tricky too. In addition to the 46th in OC, the 40th, 38th and 32nd in LA county might be ones to watch as well. It's not so much the Hispanics, but what sort of whites live there now.
Of course this is based on how things look now. There is a lot of time left and many things could change.
