SACRAMENTO, Calif. (AP) — Republicans led by former President Donald Trump are raising unsubstantiated claims that California's recall election against Democratic Gov. Gavin Newsom is rigged.

That messaging poses a problem for Republican Party officials, who are encouraging everyone to vote while maintaining concerns about the state's election security.

GOP officials have vowed to watch over the race and possibly sue to challenge any irregularities.

As of Saturday, 7.8 million ballots have been cast, or 35% of registered voters. The secretary of state says California has the nation's strictest voting system security requirements.

Much of the GOP criticism of California’s elections has focused on the wide use of mail-in ballots.