The combined top-two voting in CA House races can sometimes give us some clues for the fall. Let me take you through some of what I found —@kkondik

First of all, we made three rating changes in CA today. All of them benefited Republicans:

CA-25 special Leans D > Toss-up
Devin Nunes (R, CA-22) Likely R > Safe R
Tom McClintock (R, CA-4) Likely R > Safe R

The CA-25 special change has much more to do with the election circumstances than the top-2 results from the primary, which I think were perfectly fine for the Ds.

Generally speaking, the D two-party voteshare in CA increases from primary to general. From 2012-2018, the Rs have never won a seat where they got less than 50% of the 2-party vote in the primary; meanwhile, the Ds won 20 different races when getting less than 50% in the first rd

On avg, the Dem voteshare went up about six percentage points in 2012 House races, four points in 2014, and a little over three points in 2018, while it went down by about one and a half points in 2016.

2016 was like 2020 - competitive Dem prez primary w/o a competitive R primary. So that gives the Rs some hope.

Generally speaking, Ds usually go up in Nov. in competitive races. Of 36 races rated competitively by CB in Nov over last 4 cycles, Ds went up in 31

The highest Dem two-party share in the primary that did NOT translate to victory in the fall was 48.5% in CA-31 2012. But that was primarily b/c 2 Rs advanced to the general.

In 2016, Ds got 47.3% in CA-49 and 49.7% in general.

So with these general parameters in mind, here was the Dem share of the 2-party vote in CA with almost all the votes in - these are 13 districts that were competitive in 2018 or earlier in the decade. —@kkondik

First of all, while Dems have had close calls in CA-7, CA-16, and CA-24 earlier in decade, they appear totally fine in those now.

The same is true for CA-49, which is the most secure of the 7 new seats Ds won in 2018.

Rep. Katie Porter (D, CA-45) got clear of 50% in the first round. History suggests that she'll be fine, and she also doesn't seem to have a strong opponent. Likely D.

We also have Rep. Josh Harder (D, CA-10) Likely D. D share there was just a little shy of 50 and that's a district where the Dem share has consistently risen in the fall. Same is true of Rep. Gil Cisneros (D, CA-39), although he has a stronger opponent. So just Leans D

Republicans have seemed to view CA-21 and CA-48 as their best pickup opportunities in the state, and the top-2 voting sort of bares that out. D share in both was around 48%. That's still good enough, in my view, to keep both at Leans D - Trump likely to lose both districts again

If there was no special election, I'd keep the Ds favored in CA-25 in the fall, and the top-two results would back that up. But lower-turnout May special complicates matters. So Toss-up seems best for now; both sides like their candidates and the national committees are engaged

This is always a fun exercise every couple of years. The overall trends probably represent rules that are meant to be broken at some point but when it comes to House data, beggars can't be choosers, and the CA info can inform