Earlier this year I noted that the race for retired-Rep. Jane Harman's seat could be an early test for the new California primary system, whereby candidates for all parties compete together and if no candidate wins a majority, there is a run off between the top two candidates, regardless of party. In theory, this system could give centrist candidates a boost if support from independents and members of the opposite party enable them to get into the run-off, where they would have difficulty winning a one-party primary.
It turns out that the results from race for Harman's seat don't tell us much, but if anything they raise doubt about whether California's procedural change will bring about much real change.
In this race, the top Republican and the top Democrat grabbed the two places in the run-off, although the race for the second slot was quite close. Some speculated that the two leading Democrats might get into the run off since this is a Democratic leaning seat. But it turns out that the Republican primary voters did not use their votes to influence which Democrat won the race, but rather voted in force to get their candidate into the run-off, even though he has a small chance of ultimately winning the seat.
There are a number of explanations for this. First off, primary voters are usually committed partisans, especially compared to general election voters. It may be too much to expect (regardless of the party) that these voters will engage in strategic voting relating to the other party's candidates rather than pulling the lever for their favorite candidate of their party. The Republican voters' behavior could also be explained by the fact that they did not perceive a big difference in ideology between the two front running Democrats -- both of whom are mainstream, establishment Democrats. Thus, given the choice, they wanted to promote the Republican and give him at least a long shot chance at winning the race instead of using their vote to boost one Democrat over the other, between whom they were indifferent.
The results from this race also show that there was not much strategic voting by a large chunk of the electorate, regardless of party. This race had 16 candidates. About 25% of the electorate voted for one of the 13 candidates that had virtually no chance of getting into the run-off. The lesson from this single special election is that voters, well, at least these voters, looked the candidates over and voted for the one they liked the best.
Clearly, we need a lot more time before we can determine the effect of unified primaries.