California voters now prove who they are with a signature. Proposition 39, a Republican-backed constitutional amendment on the Nov. 3 ballot, would add a government ID requirement every time they vote.
What would change
Under the measure, people voting in person would have to show government-issued identification, according to the Legislative Analyst's Office. Voters who mail their ballots, which in the November 2024 election was about 13 million of the roughly 16 million Californians who voted, would have to write the last four digits of a government-issued ID number on the ballot envelope.
Election officials would check that number against the voter's registration before counting the ballot.
New and existing voters would have to pick a government ID in their registration to vote by mail. The state would have to give a free voter identification card to anyone who asks for one.
The measure also directs state and local election officials to make "best efforts" with government data to confirm that people on the rolls are U.S. citizens, and to report each year what share of each county's voters has been verified. The state auditor would review compliance in odd-numbered years.
Much would be left to Sacramento. The analyst's office notes that lawmakers would have to pass follow-up laws spelling out which IDs count and what qualifies as best efforts to check citizenship.
Today, a voter's identity is set when they register, using a driver's license, state ID or last four Social Security digits. Mail voters sign their envelopes, and officials verify those signatures before counting.
Cost
The analyst's office estimates state and local costs of tens of millions to low hundreds of millions of dollars a year, depending on choices such as how the ID card is designed and how many people request one. Some savings could come from a smaller voter roll, the office says, but likely not enough to cover the costs.