Nearly 150,000 ballots were not counted in California's primary election, which took place on Tuesday, June 2.
According to California data, 148,241 mail-in ballots were rejected in the primary election, representing a rate of 1.73% of the total ballots returned by the United States Postal Service (USPS).
Election experts believe the main problem is with the postmarks on ballots that arrived with a date after Election Day.
