Sergey Brin Has Spent $100M to Block a Tax That Would Cost Him $13B

Sergey Brin has now crossed the $100 million mark in donations aimed at defeating California's proposed billionaire wealth tax — a measure that, if passed, would cost him an estimated $13.3 billion. The math is straightforward, even if the strategy isn't exactly subtle.

What Prop 40 Actually Does

California's Proposition 40 — commonly called the billionaire tax — would apply a one-time 5% levy on the net worth of roughly 200 billionaires living in the state. The revenue generated would primarily fund healthcare programs, including California's Medicaid system, which stands to lose up to $30 billion in federal funding once Trump-era budget cuts take effect. It's a significant policy proposal, not a trivial line item.

Brin, whose net worth sits around $267 billion making him one of the wealthiest people on the planet, recently added another $20 million to Build a Better California, an organization working to defeat the measure, according to TechCrunch. The group has also backed opposing ballot measures that could structurally block Prop 40 by capping the introduction of new state taxes.

The Billionaire Exodus Pattern

Brin isn't operating in isolation here. A familiar pattern has taken shape among California's ultra-wealthy tech class. Former colleagues and fellow billionaires have been repositioning assets and residences in response to the growing tax pressure. Mark Zuckerberg reportedly picked up a $170 million mansion near Miami this year. Larry Page — Brin's Google co-founding partner — has also left the state, as have former Uber CEO Travis Kalanick and venture capitalist Peter Thiel.

The argument these departures make implicitly is the same one Prop 40 opponents make explicitly: tax the billionaires too hard and they take their companies, jobs, and tax base with them. It's a real concern, even if it conveniently serves the financial interests of the people making it.

Newsom's Disagreement — and His Own Proposal

Governor Gavin Newsom has actually come out against Prop 40, not because he opposes taxing the wealthy, but because he's skeptical that a state-level approach works when billionaires can simply relocate. His preferred solution is a national billionaires' tax, which would close the loophole that lets wealthy individuals borrow against stock portfolios — effectively living tax-free — while reporting no taxable income. "Today, the office worker can shoulder a higher tax rate than the heiress," Newsom wrote in a blog post outlining his position.

It's a reasonable structural critique. A California-only wealth tax creates a straightforward exit incentive, and several high-profile departures suggest that incentive is real. Whether a national version would fare better politically is a separate question entirely.

The One Guy Who Doesn't Seem to Care

The contrast worth noting here involves Nvidia co-founder Jensen Huang. Huang, who would face roughly an $8 billion tax bill under Prop 40, told Bloomberg in January that he hasn't given it much thought. "We chose to live in Silicon Valley, and whatever taxes they would like to apply, so be it," he said. "I'm perfectly fine with it."

Huang's attitude stands out precisely because it's so different from the coordinated financial opposition being mounted by others in the same wealth tier. Whether that reflects genuine indifference or savvy public positioning is hard to say — but it's a notable data point. His willingness to stay put also echoes the broader question of whether the richest tech figures are actually as mobile as they claim when their core businesses are deeply rooted in a region.

What Happens Next

California voters will decide on Prop 40 in November. Between now and then, expect the spending on both sides to keep climbing. Brin has already committed more than seven times what a typical Senate campaign costs, all to prevent a bill that would cost him 130 times that amount.

The arithmetic makes sense from a pure financial standpoint. Whether it makes sense as policy — and whether voters agree — is the part that remains unsettled.

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