Meet the California multimillionaires demanding the billionaire tax become law

California's Proposition 63 would impose a 13 percent wealth tax on residents worth more than $50 million, with rates climbing to 15 percent for those exceeding $2 billion. The measure appears on the November ballot after supporters gathered 840,000 signatures—well above the 680,000 required—and it's shaping up as one of the most expensive ballot fights in state history, with both sides already dumping eight figures into advertising. The open letter of support, signed by roughly 100 multimillionaires including venture capitalists, tech entrepreneurs, and inherited-wealth holders, explicitly frames the tax as necessary to address homelessness, infrastructure decay, and what signers call a "destabilized" middle class. This is not a fringe position among California's wealthy—it reflects a legitimate split in how high-net-worth residents view their tax obligations.

The mechanics matter here because they determine feasibility. Unlike income taxes, wealth taxes are notoriously difficult to administer and have failed in other jurisdictions. France's wealth tax, once set at 1.5 percent on fortunes over roughly $1.3 million, raised far less revenue than projected before its 2017 repeal—partly because wealthy people relocated or moved their assets. Minnesota killed its wealth tax after one year; Vermont tried and abandoned one. California's nonpartisan Legislative Analyst's Office estimates Proposition 63 could raise $19 billion over five years, but also notes significant revenue volatility depending on market performance and how many wealthy residents respond by leaving the state. Proponents say this is worth the risk; critics say the state is counting revenue that may never materialize.

The stakes are concrete for specific constituencies. Homelessness in California hasn't budged despite massive spending increases over the past decade—the state now has roughly 185,000 unhoused residents, the highest count in the nation. Schools in districts like San Francisco Unified are simultaneously cutting budgets despite serving far wealthier communities than national averages. For those signatories, the argument is straightforward: they already have wealth beyond any personal utility; California faces a genuine crisis; and it's better to fund solutions than watch the state decline. But for business owners operating at thinner margins—family-run construction firms, agricultural operations, smaller real estate holdings—a wealth tax creates existential risk, particularly if it forces asset sales to cover annual tax bills unrelated to cash flow.

The conservative position here isn't "never tax the rich" but rather "California already taxes the wealthy more than anywhere else and it hasn't solved the stated problem." California's top income tax rate is 13.3 percent, the highest in the nation. Capital gains taxes hit 20 percent when including the net investment income tax. The state's homeless population has grown even as spending rose from $7 billion annually in 2015 to over $18 billion today. The objection isn't that billionaires should pay nothing—it's that voters were already promised results, voted for spending, and got neither homelessness reduction nor infrastructure improvement. Adding another tax on the same rich people, based on the same argument, without addressing why previous investments failed, reads as pure fiscal theater. Moving billionaires out of state is a real risk, not hysteria; Elon Musk, Joe Lonsdale, and others have already relocated in recent years, taking their tax base with them.

The first test comes November 5th, when California voters decide. But the real pressure point precedes that: the state Supreme Court is reviewing whether Proposition 63 even complies with the state constitution's limits on property taxation. A ruling against the measure before Election Day could moot the whole fight. If voters approve it, expect immediate legal challenges from business groups and wealthy residents alike. The implementing details—how to value non-liquid assets, what counts as California residency, how to handle trusts and corporate structures—will matter far more than the headline rate. Those rules get written in the legislature afterward, which is where the wealth tax either becomes a genuine revenue raiser or collapses into administrative chaos. Watch that implementation battle; it's where theory meets reality.