Here is some brand new analysis from Washington state results that might shed light on the efficacy of the top two primary, which many are promoting as a good thing for CA. It is especially directed at whether the top two would elect more moderates -- or more extremists? This evidence below suggests it's a bit of a crapshoot, the top two primary could as easily elect more extremists as elect more moderates. 

In taking a look at official WA state election results at http://vote.wa.gov/Elections/WEI/Results.aspx? for last year's primary, you can see there are basically four categories of results for the 98 house races and 25 senate races.

In the first category, which has by far the vast majority of races, one candidate (usually an incumbent) is either uncontested or is so far in the lead with anywhere from 53 percent to over 70 percent of the vote and a huge enough lead that it's obvious they will win in the general (November) election as well. That includes 24 races uncontested in the primary, and 3 with only token write-in opposition. The practical impact in those races is no different from what we have now in CA, as I outlined recently in my Los Angeles Times oped.