SACRAMENTO -- If California's new open-primary law were in effect, a couple of valley elections might look a lot different today.
Instead of preparing to square off against an underdog Democrat for a spot in Congress, Jeff Denham might be readying for round two of his battle with fellow Republican Jim Patterson.
In the Assembly's 25th District, Modesto City Councilwoman Kristin Olsen would have a rematch with one of her GOP opponents, instead of cruising to Sacramento after a general election in which she will have no competition because no other parties fielded a candidate.
Proposition 14, which passed Tuesday 54 percent to 46 percent, allows only the top two vote-getters in a state or congressional primary election, regardless of party affiliation, to advance to the general election. Voters can cross party lines, and candidates don't even have to list their affiliation.
The new system starts in 2011, unless it is overturned in the courts. Political parties, which oppose the system, have all but guaranteed they will fight it, but they might wait until after it takes effect.
If it stands, open primaries will have the biggest effect beginning with the next round of state elections in 2012. That's the same year candidates will be competing in newly drawn political districts.
Legislative seats will be drawn by a panel of average citizens for the first time, and the Legislature will keep control of congressional mapping.
All told, elections might look much different in the coming years, although experts say a lot depends on how the new districts look, which no one is able to project.
"There is going to be change. Time will tell what that change is going to be," said political analyst Allan Hoffenblum, who studies legislative and congressional races.
There's no telling how voters will react. Supporters of the open primary predict races will be more competitive, the electorate will be more engaged and candidates will broaden their message to appeal to everyone in the district, as opposed to wooing only the partisans who tend to vote in closed primaries.
But Jessica Trounstine, a political science professor at the University of California at Merced, said there's a good chance turnout won't increase because voters still will perceive the primary as being less important than the general election.
"I think the primary electorate will remain how it is," she said. "I think that there's good reason to think that moderation would not occur."
A recent study suggests that elections in the valley might not look all that different. Looking at historical trends, the nonpartisan Center for Governmental Studies found that more than one-third of state legislative and congressional races could produce general election contests between two members of the same party. But those races would occur only in districts where one party has a supermajority of registered voters, which is currently not the case in any valley district, the study found.
In the 19th Congressional District, the Republican turnout was so high Tuesday that as of the latest ballot count Friday, former Fresno mayor Jim Patterson was neck-and-neck with the leading Democrat, Dr. Loraine Goodwin. She led him by 234 votes. Under the open primary, he would move on to November if he got more votes.
Of course, voters and political parties might have behaved differently had the new system been in place. So it's hard to say what the outcome would have been under an open primary. Democrats, for instance, might have had more of an incentive to show up and move one of their own to November.
But there's also the chance that one of the four Republicans running in the 19th would have made a broader appeal in hopes of luring more independents and Democrats.
Hoffenblum said any change is better than the system in place now, which he said results in a "Disneyland of ideologues."
But Ron Nehring, chairman of the state GOP, said open primaries will disenfranchise Republicans who in some cases won't have a chance to vote for their nominee in districts that produce a Democrat-only general election showdown. That's most likely to occur in some Bay Area and Los Angeles County districts, according to the Center for Governmental Studies report.
To protect against getting shut out in general elections, Nehring said, political parties might seek to use their influence to narrow the number of candidates running from their party. The fewer number of candidates, the better chance of moving on to November.
"It is an inevitable byproduct of this very poorly thought-through law," he said.