A proposed billionaire tax in California is facing significant opposition from wealthy donors who are funding efforts to block the measure. Google co-founder Sergey Brin has contributed $45 million to a political group working to defeat the wealth tax proposal, according to campaign finance records.

Opponents of the tax are expected to spend approximately $75 million total in their campaign against the measure. The substantial financial opposition has driven up costs for signature collection, with campaigns now paying $15 per signature to petition distributors.

The California billionaire tax proposal represents part of ongoing debates over wealth taxation at the state level. Supporters argue such measures could generate significant revenue for public services, while opponents contend they could drive wealthy residents to relocate to other states.

The signature collection process has become increasingly expensive as political groups compete for petition distributors. The elevated rates reflect the high stakes both sides see in the outcome of this tax proposal.

Brin's $45 million contribution represents one of the largest individual donations to oppose the wealth tax. The substantial sum has drawn attention to questions about political influence and the role of wealthy individuals in shaping tax policy that would directly affect them.