One of the more interesting developments on the June 8 “Super Tuesday Primary” day was the approval of a ballot initiative (Prop 14) by California voters creating a “top two” voting system. Similar to the process already used in Washington State, it essentially abolishes party primaries and provides that the top two finishers in a nonpartisan primary will proceed to the general election.
Over at Sabato’s Crystal Ball, TDS contributor and advisory board member Alan Abramowitz of Emory University has examined the claims of Prop 14 backers like Arnold Schwarzenegger that the new system will reduce ideological and partisan polarization in California, and concludes it’s pretty much a nothing-burger. He takes on two particular illusions associated with Prop 14: the idea that party primaries and gerrymandering are responsible for political polarization in California, and the idea that abolishing party primaries will prevent ideologues from winning elections.
On the first topic, his reseach shows:

The most important source of polarization in California politics is the ideological divide between supporters of the two major parties….In both California and the nation, ideological polarization increased considerably over this time period, but it has always been greater in California. That’s because while California Republicans are as conservative as Republicans in the rest of the country, California Democrats are considerably more liberal than Democrats in the rest of the country.

And on the second topic:

In Washington, which began using the new system in 2008, the electoral consequences were minimal. In all 9 of the state’s congressional districts the open primary produced a general election runoff between the Democratic or Republican incumbent and a challenger from the opposing party and in all 9 general election contests the incumbent was victorious. And based on the winners’ voting records in the 111th Congress, the new primary system has had no effect on partisan polarization–the gap between the state’s Democratic and Republican representatives was just as large in the current Congress as it was in the previous one. Expect the same results in California.

So can we just forget about Prop 14? That’s not quite clear just yet. The new system could produce some strange and unintended consequences.
For one thing, making the primary non-partisan could be a major boon to self-funders, who may simply need high name ID to win a general election spot, particularly in California statewide races where the cost of television advertising will be prohibitive for many candidates. For another, the system could theoretically increase partisan polarization. The “top two” system does not provide any particular incentive for winning an actual majority of votes in a primary; the top finisher still must face the runner-up in the general election, where turnout is very likely to be much higher. So the safe thing to do is to nail down a general election spot by appealing to partisans (Prop 14 does not repeal party registration, which means that candidates will know exactly whom to contact with partisan messages), while beginning the general election campaign by going after the other party’s preferred candidate.
Consider this year’s governor’s race. If Meg Whitman were running with her vast fortune in a “top two” system, perhaps she would not have spent quite so much time attacking Steve Poizner for alleged ideological heresy. But on the other hand, she would have had every incentive to go after Democrat Jerry Brown (whom she largely ignored) hammer and tongs to drive up his negatives in preparation for November.
In effect, Prop 14 makes the general election cycle a lot longer. That does not seem to be a particularly smart way to reduce partisan polarization.