The polls closed across California at 8 p.m. in Tuesday's Presidential Primary Election.
California's voter registration reached a record high of 17.9 million as nearly 650,000 people registered to vote in the state between the April 8 and the May 23 deadline, the Los Angeles Times reported.
The majority of the newly registered voters -- approximately three out of four -- are Democrats, the newspaper reported.
The Field Poll, an independent and non-partisan survey, estimates that about 8 million voters will be participating in the California presidential primary Tuesday.
An estimated 5 million voters will vote by mail, a record for a primary election in the state.
In L.A. County, voter turnout was roughly 35.55 percent at 7 p.m., according to Dean Logan, the Registrar-Record/County Clerk, citing a non-scientific sampling.
That figure is higher than the 23.55 percent that showed up in the 2012 presidential primaries, but lower than in 2008, when turnout was 51.16 percent, he said.
Multiple voters contacted KTLA expressing concerns about their polling places, but no major issues have been reported.
The Associated Press, CNN and other media outlets called Hillary Clinton’s race against Bernie Sanders on Monday night, but the former first lady was not ready to declare victory ahead of today’s primaries in North and South Dakota, Montana, New Jersey and New Mexico.
"I got to to tell you, according to the news we are on the brink of a historic, historic, unprecedented moment, but we still have work to do, don't we?" Clinton told supporters in Long Beach Monday. "We have six elections tomorrow and we are going to fight hard for every single vote, especially right here in California."
KTLA's Tracy Bloom contributed to this story.