When your former political ally turns around and calls your signature policy a "commie" tax, you know the conversation has gone sideways. That's exactly what happened when venture capitalist Vinod Khosla unleashed a blistering critique of Rep. Ro Khanna's proposed California billionaire tax, warning it could permanently wreck the state's economic foundation.

The Tax That's Already Causing an Exodus

In a pointed post on X, Khosla didn't pull punches. He claims that Khanna's support for the proposed tax has already caused half of California's top $2 trillion in wealth to pack up and leave. And if the tax actually passes? Khosla predicts permanent damage to the state's tax base as those departed billionaires stop contributing revenue forever.

Here's what makes this particularly spicy: Khosla was one of the top Silicon Valley supporters and donors for Khanna's early congressional campaigns. Now he's calling the congressman's actions "dumb," motivated by personal ambition, and destructively short-sighted. Khosla even warned that non-billionaires are planning their exits too, spooked by the prospect of future tax escalations.

The proposal itself is aggressive. It would slap up to 5% annual taxes on California residents with net worth exceeding $1 billion, plus impose a one-time $1 billion tax on anyone holding at least $20 billion in assets as of January 1. That's not pocket change, even for the ultra-wealthy.

Silicon Valley Sounds the Alarm

Khosla was responding to Garry Tan, CEO of Y Combinator, who warned the billionaire tax could effectively kill California's startup ecosystem. Tan's concern is straightforward: extreme tax uncertainty drives founders out before their companies succeed and discourages new entrepreneurs from even starting businesses in the state. It's hard to build the next big thing when you're worried about a massive tax bill before you've even gone public.

The debate quickly pulled in other tech heavyweights. David Sacks, White House AI and crypto czar and prominent investor, took a shot at Khanna's political calculus. Sacks suggested Khanna isn't foolish, just ambitious, and questioned why the congressman sees political upside in what Sacks characterized as "asset seizures." His implication? The Democratic Party might be moving in an increasingly aggressive direction on wealth taxation.

Meanwhile, Sam Bahreini, founder and CEO of Konstellate, an AI-powered pharmaceutical intelligence platform based in New York, called out Khosla and other early Khanna backers for their role in creating this situation. His message was blunt: take responsibility for the consequences of your past support.

The Billionaires Are Already Moving

This isn't just theoretical hand-wringing. High-profile figures are already responding to the tax threat. Alphabet Inc. (GOOGL) Google co-founders Larry Page and Sergey Brin have started reducing their California ties, adding real-world fuel to concerns about the proposal's economic impact.

Khanna, for his part, has remained a steadfast defender of the billionaire tax despite mounting criticism from some of the state's wealthiest and most influential residents. He's betting that the political benefits of taxing extreme wealth outweigh the risks of losing some billionaire residents.

What we're watching is a fundamental clash over California's economic future. Can the state afford to lose its wealthiest residents? Or can it afford not to tax them more aggressively? Khosla's warnings underscore a growing divide within California's tech sector, where political allegiances that once seemed solid are fracturing over tax policy. The irony is hard to miss: the venture capitalists who helped build California's tech economy are now threatening to leave it, and taking their capital with them.