The filing came after a steady stream of complaints throughout the county of faulty machines and two-hour waits in neighborhoods including Westwood, the San Fernando Valley, Los Feliz and the east side of Los Angeles. The sign-in process to check voters against the voting rolls was taking hours at several sites.

Earlier in the day, a power failure in West Los Angeles had raised worries that the voting process could be delayed.

For weeks, state and county officials have been warning of long lines on Election Day, in part because of the new system and also because voters could register in person on Tuesday.

There were reports of two-hour waits at several polling places throughout Los Angeles County, with poll workers directing voters to other sites that had equally long waits. Several machines reportedly failed, leaving many voting booths sitting empty and leading to even longer waits. At one polling place, a poll worker handed out candy to weary voters, and campaigns sent pizza to several voting sites at the University of California campuses.

[Sanders files emergency motion to keep polling places open in L.A., after delays.]

The line outside the Claude Pepper Senior Citizen Center in West Los Angeles curled around a courtyard that was mostly in the shade by late afternoon. An election worker at the facility said its five voting machines were working fine, but having just one check-in tablet computer created a bottleneck, leaving two or three of the voting machines empty.

Vickie Trosclair, 85, was inside the building near the front of the line, and said she had been waiting to vote for over two and a half hours. She is a day care provider, and was worried she would not be back by the time parents came to fetch their kids.

“I thought I could just do this and be back,” she said. “This operation is much too slow. The line is too long, it’s too crowded.”