alt Hacker NewsI think you've misunderstood the proposal. The government levies a tax in the form of shares, not cash. It doesn't pay for the shares.
FTA: "It would create a sovereign wealth fund through a one-time 50 percent tax — not on the profits of OpenAI, Anthropic, xAI and other companies, but paid with something far more valuable than that: the stock."
That seems like it would be pushing pretty hard against the Takings clause. Federal wealth taxes in general are rather precarious in the US because the 16th amendment allows taxing income, not assets.