Tracking a California governor's vetoes means watching two calendars: the one that ends each September, when the governor must act on every bill sent from the Legislature, and the one that almost never starts, the override vote. In 2024, Gov. Gavin Newsom vetoed 189 bills, and about 90% of them had passed with support from more than two-thirds of lawmakers in both chambers, according to CalMatters. That's enough votes to override him. None did.
The mechanics are set out in the state constitution, and they're simpler than the politics around them. Once the Legislature sends the governor a bill, the governor has a fixed window to sign it, let it become law without a signature, or veto it. The path a bill takes from introduction to the governor's desk shapes when that window opens each year, and it always closes in the same place: a pile of bills awaiting action at the end of summer.
Understanding vetoes means understanding why an override almost never follows one. This guide covers how the veto works, where to find the paper trail, and why the two-thirds threshold that should make overrides routine has instead made them all but extinct.
How does the governor's veto actually work?
The California Constitution gives the governor a set period to sign or veto each bill, and any bill left untouched becomes law without a signature. A veto message is a legal requirement, not a courtesy. The governor has to explain, on the record, why the bill didn't get signed.
Those messages matter for tracking purposes because they're the single most reliable public document showing why a bill died. According to an analysis cited by CalMatters, lobbyist and Capitol-watcher Chris Micheli found that in 2024 Newsom rejected 30% of bills over budget concerns, 27% over policy disagreements, and another 22% because he judged them unnecessary or overlapping with other agencies' authority.
Cost concerns show up often, and they can be broader than they look. The American Prospect reported that Newsom's veto messages sometimes cited a combined "nearly $19 billion" of unaccounted-for costs, a figure that covered all bills sent to him that session, including many he signed, not just the ones he rejected, according to The American Prospect.
How often does a governor veto bills in California?
Vetoes are a routine part of the legislative year, not an exception. The American Prospect reported that governors have vetoed at least 10% of bills presented to them every year since 2004, with one outlier: Newsom vetoed just 7.89% of bills in 2021, before that rate climbed to 14% in 2022 and roughly 15.7% in 2024, according to The American Prospect and CalMatters.
Those percentages translate into real bills with real sponsors. In 2024, the governor blocked a measure that would have required licensing for pharmacy benefit managers, the companies that sit between insurers and drug manufacturers on pricing. It passed 70-0 in the Assembly and 38-2 in the Senate, according to CalMatters. State Sen. Scott Wiener, the bill's author, called the veto "a really, deeply bad veto" but stopped short of pushing for an override.
A veto doesn't always mean a policy is dead for good. Sponsors can reintroduce a bill next year, sometimes rewritten to answer the governor's stated objection. That's slower than an override, but it's the path nearly every vetoed bill actually takes.
Why doesn't the Legislature override vetoes if it has the votes?
The threshold for an override is a two-thirds vote in each chamber, the same supermajority needed to pass many bills in the first place, under Article 4, Section 10 of the state constitution, according to the National Conference of State Legislatures. With Democrats holding 93 of 120 seats as of 2024, that math is available almost every session. It's just never used.
The last time it was used, the year was 1979. Then-Gov. Jerry Brown had a bill overridden that barred banks from selling insurance, authored by then-Assemblymember Lou Papan, according to CalMatters. It was the second override of a Brown veto in eleven days. Nothing like that streak has happened since.
Politics professor Dan Schnur, who teaches at UC Berkeley, USC and Pepperdine, offered a blunt explanation to CalMatters: a governor who gets overridden tends to issue more vetoes afterward, especially against the lawmakers who crossed him. In a chamber where the governor still controls appointments, budget priorities and future signatures, few members want to be first through that door.
Politics professor Thad Kousser of UC San Diego framed it differently: legislators sometimes prefer to let the governor be the one who kills a popular bill, so they never have to cast a vote against it themselves, according to CalMatters.
How the legislative calendar blocks an override before it starts
Timing does as much work as politics here. Bills must be introduced by February, cleared out of committee by April, passed out of their originating chamber by May, and through both houses by the end of August, under the schedule described in The American Prospect's reporting. That leaves a backlog of bills landing on the governor's desk right as the Legislature adjourns for the year.
By the time lawmakers reconvene, months have passed since the veto. In odd-numbered years, that gap tends to cool whatever urgency existed. In even-numbered years, it's worse: the Legislature that returns is a newly elected one, and a new session cannot revive a veto from the old one. The twelve-year term limits reshaping the Legislature add turnover on top of that calendar gap, meaning the members who voted for a bill may not be the ones still in office when an override might be considered. We covered a connected angle in Twelve Years and Out: How Term Limits Remade the California Legislature.
Practical steps for tracking a veto or a possible override
Readers who want to follow a specific bill, not just the year's veto count, have a workable routine. It takes patience, not special access.
- Note the bill number as soon as it clears both chambers, since veto messages are filed under that number and searchable by it.
- Watch the deadline window at the end of the session; that's when the governor must act on the full backlog at once.
- Read the veto message itself, not just news coverage of it. It states the stated reason on the record, whether cost, policy disagreement, or redundancy with existing law.
- Check the original vote margins in each chamber. A two-thirds margin in both the Assembly and Senate means an override is constitutionally possible, even if it's never been politically likely since 1979.
- Track whether the bill's sponsor reintroduces it the following session, which is the far more common outcome than an override attempt.
None of this requires guessing at legislative intent. The vote count, the veto message and the reintroduction, if any, are all part of the public record.
What this means for California voters and residents
The gap between a governor's veto power and the Legislature's override power isn't hidden anywhere. It's built into how rarely one branch checks the other once a supermajority exists on paper but not in practice. For residents, that means a bill with near-unanimous support, the kind covering drug pricing or paid leave, can still die on a single signature with no further vote.
That has a direct cost for anyone counting on a specific bill's outcome for household finances, health care access or workplace protections. A vetoed bill isn't necessarily gone, but the path back is usually a new bill next year, not a floor vote reviving the old one. Readers tracking California's budget process and its own supermajority thresholds will recognize the same math working differently in a different context: the votes exist, but the incentive to use them against the executive rarely does. Readers following this should also see California's Top-Two Primary, Explained Before the June Vote.
The record is public, the thresholds are fixed, and the pattern has held for more than four decades. What changes year to year is which bills get caught in it.