1 of 2
Sandy Huffaker, File, Associated Press
FILE - In this Sunday, June 5, 2016 file photo, Democratic presidential candidate Sen. Bernie Sanders, I-Vt. speaks during a campaign rally at Qualcomm Stadium in San Diego. State officials are preparing to embrace an expanded California electorate Tuesday as nearly 18 million registered voters head for the polls or turn in early presidential primary ballots.

SACRAMENTO, Calif. — California election workers opened polling stations and continued counting early ballots with few hiccups Tuesday as county clerks embraced an expanded electorate totaling nearly 18 million registered voters.

A surge of 650,000 new voters less than two months ahead of the June 7 primary set up a potentially big turnaround from the historically low turnout of 2014.

But presidential elections draw more people to the polls and county clerks are expecting turnout to reflect the drawn-out contest for the Democratic Party's presidential nomination. Elections officials in San Diego and Santa Clara counties are expecting at least 55 percent of registered voters to cast ballots. Contra Costa has been planning to accommodate 60 percent of registrants, and Alameda is hoping to hit 70 percent.

The Associated Press reported Monday that former first lady, New York senator and Secretary of State Hillary Clinton secured the number of Democratic delegates needed to become the party's presumptive presidential nominee.

The announcement angered supporters of Vermont Sen. Bernie Sanders, who is competing for the party's title, but it also concerned nonpartisan organizations focused on increasing voter participation.

Kim Alexander, president of California Voter Foundation, said she was disappointed that the AP released its count hours before the California primary — one of the nation's last — because it has the potential to suck the air out of the election. But she said a steady flow of voters at the polls seemed to indicate the call had little if any effect on the race by mid-Tuesday.

"There are a lot of people trying to participate in this election despite the Associated Press prediction that this election is over, so we're happy to see that," Alexander said.

In one quickly resolved incident, Contra Costa County Assistant Registrar of Voters Scott Konopasek said volunteers in the heavily Democratic East Bay county thought they lost what few Republican ballots they needed for the cities of Pittsburg and Bay Point.

"There were a couple of places that had stacks and stacks of Democratic ballots because they have stacks and stacks of Democratic voters," Konopasek said. "They only had one or two pads of Republican ballots, and they just got lost in the shuffle. But when we went through it all, there they were."

The Los Angeles County registrar's office was looking into at least one report of a polling place that was not up and running at the state's 7 a.m. start time.

More than 3.1 million Californians had cast ballots before the polls opened Tuesday, more than two-thirds of all voters in the 2014 primary. Just 25.2 percent of registered voters participated in the 2014 primary and 42.2 percent in the general election.

Although only one statewide initiative appears on the primary ballot, petitioners have turned in signatures for 20 more initiatives they hope to get on the Nov. 8 ballot. Counting those signatures and processing voter registrations have strained county election offices, some of which had to hire temporary workers to handle the workload.

The Field Poll predicts that two-thirds of voters will cast ballots by mail.

About 4.1 million California voters this year are Latino, 1.6 million are Asian, and 800,000 are black.