California’s June primary saw almost 150,000 mail-in ballots rejected, the highest tally in recent statewide elections, with lateness the primary driver at 93,479 rejections. Despite a seven-day postmark grace period, ballots arriving late or with postmarks after Election Day appear ineligible, highlighting concerns about USPS processing changes. Experts and advocates note that changes in postal timing and routing may cause postmarks to reflect processing dates rather than mailing dates, complicating eligibility. The rise in late rejections has drawn scrutiny from voting researchers and policymakers, who point to the need for investigating what is driving the delays and whether the system is undermining access. California has long aimed to expand turnout with universal mail voting and extended acceptance windows, but the data suggests the state’s promise of easier voting is not yet realized in practice. Advocates emphasize the importance of ensuring ballots are counted while maintaining the integrity of the voting process.