LOS ANGELES (AP) — A series of changes in California meant to boost voter turnout and smooth its new Super Tuesday primary election led to a surge in last-minute voters, computer problems and short-staffing that appeared to catch elections officials by surprise, triggering scathing criticism Wednesday.

Long lines, sluggish computer connections and general confusion plagued polling places statewide — raising serious questions about the ability of the most populous state to handle November's general election, when millions more voters are expected. Critics called for an overhaul before then.

Los Angeles County rolled out a new $300 million voting system, including new scanning devices and voting machines that the state certified despite known security and technical problems. Many of the voting devices didn't work and there were not enough check-in machines or poll workers, leading to wait times of two hours or more.

Bernie Sanders' presidential campaign filed a legal complaint in the county that has more than a quarter of California's 20 million voters, a county supervisor demanded an investigation and a Democratic Party leader gave a stinging rebuke of the “abysmal" infrastructure.

“It was an overwhelming experience during a time where voter turnout should have been high," county party chairman Mark J. Gonzalez said in a statement. “It's Turn OUT, not Turn AWAY."

Secretary of State Alex Padilla, a Democrat who oversees California's elections, did not respond to multiple requests for detailed explanations Tuesday and Wednesday.

The state voter database was not available part of Tuesday, so poll workers in 15 counties could not print out ballots, register voters or check whether voters had already cast ballots. Some counties said the system was slow all day. A spokesman for Padilla said there was no evidence of malicious activity but did not explain what caused the failure.

“We tried a lot of new things, and we’re going to need to make adjustments," said Kim Alexander, president of the nonpartisan California Voter Foundation. “It was not good timing to roll out all this new technology in a major election.”

A crush of voters in the 15 counties that replaced traditional neighborhood polling places with fewer multipurpose vote centers delayed the reporting of results in some counties. The centers, where people could register and vote, were designed to make voting more convenient.

In Butte County in Northern California, registrar Candace Grubbs said she delayed reporting initial results Tuesday night because so many voters were still in line and she didn't want to influence their vote.

Connections to the state database were sluggish all day, contributing to the long lines, she said.

“Voting centers were designed by academic liberals, but are not practical,” said Bob Mulholland, a Democratic National Committee member in Chico. “I’m very disappointed that California, technology capital of the world, has lines four or five hours long and software that’s breaking down all over the place.”

Mulholland said he warned early on that voting centers did not make sense in a densely populated state like California, where many voters live in cities. He said he received calls Wednesday that the last Butte County votes were not cast until 12:20 a.m.

“California brags about early voting — actually it ended up causing late voting,” he said.

State lawmakers will likely launch an informal inquiry after ballot counting concludes, said Democratic Sen. Tom Umberg, chairman of the Elections and Constitutional Amendments Committee.

“Our job is to do better. That’s our job. So if people decided not to vote because the lines are too long? That means we need to fix it," he said. “We don’t want to have people waiting in long lines in November."

A bottleneck of angry voters led to wait times of up to four hours in Los Angeles County, according to Sanders' lawsuit filed late Tuesday. He went on to win California, which has the nation's largest haul of Democratic delegates.

Los Angeles County Supervisor Janice Hahn called the problems unacceptable and called for an investigation to be completed within 30 to 60 days.

“Certainly you expect some bugs in the system, but I was uncomfortable with what I was hearing yesterday," she said Wednesday.

County Registrar-Recorder Dean Logan apologized late Tuesday. He called it “a challenging day" and acknowledged that the system in which 979 vote centers replaced more than 4,500 polling places “needs quite a bit of refinement." He hasn't responded to repeated requests for more details.

The county's new touch-screen voting devices, meant to boost accessibility, operated slowly at times because so many voters were trying to use them at once, said Mike Sanchez, a spokesman for Logan. More devices were added at some polling places and there were no indications of security breaches, he said.

“I think we perhaps overestimated how many of those voters would take advantage of the early voting period," Logan said.

Election integrity activists had warned that the county's system was bound to experience serious failures and should never have been certified by the state. Technical and security defects had been identified in testing, including the ability for attackers to bypass seals, locks and sensors and boot from a USB port, which could allow election data to be modified.

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Har reported from San Francisco. Associated Press journalist Juliet Williams in San Francisco contributed to this report.