The results of California's inaugural "top-two" primary are in, and some voters will be seeing double in November.

In about one-sixth of the state's legislative and Congressional races, either two Democrats or two Republicans will be on the ballot as a result of Tuesday's primary that sent the leading two vote-getters into a November runoff. Democrat will face Democrat in 18 races, and Republican will battle Republican in eight more.

But while many feared the new top-two system would severely limit voter choice, the vast majority of California's legislative and House battles will still pit Democrat against Republican -- especially in battleground districts. Most of the homogeneous races are in districts already deemed safe by the party that will monopolize November's ballots. Eighteen of the single-party races are state Assembly battles.

As expected, though, the biggest casualty from Tuesday's foray into a top-two primary were third-party candidates: Not one made it through to November's ballot in the 153 state and federal legislative races. But five no-party-preference candidates -- four for House seats, one for an Assembly seat -- will face off against major-party candidates in November.

Voters approved the new system in 2010 with Proposition 14, billed as a way to force politicians to become less extreme and more pragmatic. It was the brainchild ofAbel Maldonado, then a Republican state Senator from Santa Maria who ransomed his

state budget vote to force legislative Democrats to put the measure on the ballot.

On Tuesday, Maldonado took part in the state's first top-two primary, placing, second in the 24th Congressional District race and advancing to a November showdown with incumbent Democrat Lois Capps, D-Santa Barbara.

But Maldonado on Wednesday pointed to another race -- the East Bay's 15th Congressional District -- to illustrate why the top-two system is "a giant, firm step in the right direction."

That extremely safe Democratic district now has Democrat Eric Swalwell nipping at the heels of 20-term incumbent Rep. Pete Stark, D-Fremont, after besting a conservative independent in Tuesday's primary. In an ordinary primary, Stark would've won, a Republican nominee would've had no chance, and the race essentially would be over.

"Mr. Stark cannot kick back and relax. He's got to campaign, he's got to keep talking to the people in that district ... and that's good for that area," Maldonado said. "I can guarantee you that the candidate who wins that district will be the one who can communicate with some Republicans and independents, and that person's voice will be a voice of reason and he will go on to victory."

Darry Sragow, a veteran

Democratic campaign strategist who founded No Labels, a nonpartisan nonprofit "dedicated to breaking the stranglehold that the extremes have on our political process," said Tuesday's primary must be seen as just the beginning.

"It's part of a process that is beginning to pick up speed,'' he said, " that reflects a lot of voters and a number of political insiders who are incredibly frustrated with gridlock in government and are in a variety of ways trying to crack the system open."

Democrats hope to pick up House seats in California as part of their national "Drive to 25" effort to recapture the chamber this fall. They also hope to widen their state legislative majorities to the two-thirds needed to pass tax bills -- a possibility in the state Senate, a much longer shot in the Assembly. Both Democrats and the GOP were talking tough on those races Wednesday, particularly the House battles.

Corey Cook, a political science professor who directs the University of San Francisco's Leo T. McCarthy Center for Public Service and the Common Good, said Tuesday's results show the new top-two system could have a greater impact on Republicans -- particularly in the Assembly -- than anyone else.

With so many Republican-on-Republican races in the Assembly compared to the number of seats the GOP already holds, he said, those candidates must consider how to prevail in November. Do they adhere to strict ideological principles, such as signing no-tax pledges or do they behave moderately to attract the independent and Democratic votes that could buoy them to victory?

Cook worries that such candidates, as well as liberal Democrats facing off against their peers, might choose to cloud their true records and ideals to pose as moderates.

"I'm not convinced this system is actually going to work," he said. "It might lead to less substantive November elections that are less about issues and more personal, more about framing your opponent as an extremist."

Josh Richman covers politics. Follow him at Twitter.com/josh_richman. Read the Political Blotter at IBAbuzz.com/politics.