Successful candidates will need to appeal to a broader swath of voters and can no longer restrict their primary campaign spending and activities to members of their own party, Pitney said. "Trying to identify who is going to vote for you is tricky."
Candidates won't be successful if they try to appeal to a "broader swath of voters." Republicans will select a Republican. Democrats will select a Democrat. Some independents always vote with one party and will continue to do so. Members of third parties, and those that vote with them, will continue to do so. They can vote for the eventual winner in November the same as everyone else. DTS voters have always been able to request a ballot from whichever primary they wished to vote in. So this won't be that much different for them either.
We can go to the CA-36 special election last summer for guidance. That election had 6 Republicans, 5 Democrats, a Libertarian, a Peace and Freedom, and 3 independents. No one in the race got even 25% of the vote and Craig Huey needed only 22% to qualify for the top two election. Hahn appealed to her labor union/minority base, while Huey appealed to fiscal conservatives and evangelical voters. Debra Bowen appealed to progressives. She either didn't get enough of them to the polls or there weren't enough in the district for her to make top two.
Open seat primaries in CA-1, 2, and 8 have drawn a lot of candidates from the more dominant party and either one or two from the other party. The five or six candidates in the dominant party will have to set their focus just as narrowly as they would otherwise and go after their, hopefully, unique constituency. There are two liberal activists in the CA-2 field. These two will draw their votes from progressives and Occupy types. State Assemblyman Jared Huffman would be foolish to go after them.
If Jim Reed wants to advance in CA-1, he needs to narrowly focus on people who always vote Democratic. That'll be 30%+ of the electorate, enough to make top two if he can get almost all of them.
Districts like CA-3 will have one Democrat, incumbent Congressman John Garamendi, and four Republican challengers. Republicans would be wise not to try to appeal to Democrats in the race. They won't snag moderate Democrats looking for the most moderate candidate. They'll vote for Garamendi. In fact, they'll need to vote for Garamendi to make sure he makes the November election. Normally, he'd advance because he'd be the only Democrat. He certainly doesn't need all the Democratic votes to advance, but if enough of his voters decided to vote for Republicans, he wouldn't. Those that do vote in the Republican primary will vote for the weakest Republican, not the most moderate one. They'll want to select the candidate that'll be easiest for Garamendi to beat.
There are some no party preference candidates who'll try to appeal to members of both parties, but I doubt this'll work well. People don't have to join a party. Those that do tend to be loyal.
Most observers expect that all these races will head into the November runoff with two Democrats on the ballot.
Not most observers who have studied the top two in Washington. In order for Berman and Sherman to both advance, Republican challengers Susan Shelley and Navraj Singh will need to siphon off significant votes from favorite Mark Reed for both Berman and Sherman to advance. It may happen, as the Republicans are going after a smaller pool of voters. I'd put it as 70-75% likely that both Berman and Sherman won't advance.
There are only two candidates in the CA-44 race, incumbent congressmen Janice Hahn and Laura Richardson. So both will advance and the real battle will be in November.
There are a few races, CA-13, 15, 29 and 35, where there are no Republican candidates. There is an incumbent Democrat, however. The person who advances will likely be the candidate who can run furthest to the right, not the center, because the Republicans are more up for grabs than the Democrats.