"So we know there's about a million gap there," said Dean Logan, with the registrar office.
RELATED: Are you registered to vote? Find out here
Those one million people still have time to register before the cut off day on Monday. Community engagement personnel from Alta Med healthcare providers in Commerce made a last pitch to people.
"I feel like I need my voice heard," Desiree Varela said.
So what makes 1 million people hold off? Dean Logan said there are questions, especially about millennials.
"It's not so much apathy. It's more about making that connection between voting, being meaningful, to other things that they're already doing in civic life, like volunteering and that type of thing," Logan said.
2018 VOTER GUIDE: A look at the California governor's race
Another issue has a quick fix and it's knowing how to register. Potential voters can log on to lavote.net. There is also a link if anyone wants to verify their registration status.
"Make sure that we have your address right. Make sure that you know your polling place," Logan said.
In the last primary, a software glitch erased the name of 118,000 voters from the roster. Logan said that has been fixed. But what if there's another problem?
"Don't be turned away. You have the right to have that provisional ballot and to be sure that you have an opportunity to cast the ballot," he said.
For more election-related stories, head to abc7.com/vote.