‘Grow the damn economy’: Billionaire Ken Griffin warns Trump made a mistake cutting taxes as the national debt tops past $40 trillion

Ken Griffin has spent millions helping Republicans win elections.

But the Citadel founder says President Donald Trump and his party made a mistake by renewing tax cuts without room in the budget to pay for them.

“We didn’t have the fiscal space to renew the tax cuts,” Griffin said Tuesday at the Future of Global Markets Conference in New York, pointing to the government’s heavy pandemic spending and a national debt that has surpassed $40 trillion.

His criticism centers on Trump’s One Big Beautiful Bill Act, which kept the lower individual income tax rates from the president’s 2017 overhaul permanent, instead of letting them expire at the end of 2025.

Along with preventing that tax increase, the law added deductions for qualifying tips and overtime pay, as well as certain auto loan interest.

However, preserving those savings for taxpayers also means Washington collects less revenue than it would have if the cuts had expired.

With the government already spending more than it brings in, Griffin’s concern is that Republicans extended the relief without enough room in the budget to absorb the cost.

His criticism hasn’t stopped him from putting millions behind the party, including $10 million to the Senate Leadership Fund and $5 million to the Congressional Leadership Fund this election cycle to help Republicans secure seats in both chambers of Congress.

He also gave $10 million in support of Florida’s gubernatorial nominee, Byron Donalds.

The cost of keeping taxes lower The cost of the legislation extends beyond the revenue Washington gives up, and borrowing to cover the gap also means paying interest.

The Congressional Budget Office estimated that the law’s tax and spending changes would add $4.1 trillion to federal deficits over 2025–2034, including interest on the additional borrowing.

That estimate does not account for how the law’s effects on the economy could change federal revenue and spending.

Those projected costs add to a debt burden accumulated under both Republican and Democratic administrations, now totaling approximately $40.4 trillion .

That includes debt held by investors and obligations to government accounts.