Brin has personally contributed about $82 million to the campaign, according to state campaign finance records, making him the driving force behind the effort. Operating under the name Building A Better California, the coalition also includes prominent Silicon Valley investors such as John Doerr and Michael Moritz.
Rather than only urging voters to reject Proposition 40, which would impose a one-time tax on California residents with a net worth exceeding $1 billion, the coalition has placed competing measures on the November ballot. Under California law, if both proposals pass, the measure receiving the most “yes” votes will take effect, a strategy designed to weaken or block the original initiative.
The campaign is expected to become one of California’s most expensive ballot fights this year, highlighting the growing political influence of the technology industry’s wealthiest leaders. Supporters of the wealth tax argue it would generate funding for public priorities, while opponents, including Brin’s coalition, warn it could discourage investment, entrepreneurship, and long-term economic growth.