It isn’t right to tell a middle-class or economically challenged family making $50,000 a year “it’s going to cost you 20%, 30%, 40% more for your groceries, for your toaster, for a new vacuum cleaner, for a new car,” Griffin said. “Even if the dream of jobs coming back to America plays out, that’s a 20-year dream. It’s not 20 weeks. It’s not two years. It’s decades.”

Speaking at an event celebrating the centenary of the University of Miami, the Citadel founder urged audience members to reach out to Trump to encourage the president to take a step back.

Griffin, 56, is part of a growing roster of prominent finance executives who have spoken out about the risks of Trump’s tariff policy since it was announced last week, triggering a stock rout that’s wiped trillions of dollars from global equity markets and caused other nations to threaten their own countermeasures.

Hedge fund manager Bill Ackman, a prominent Trump supporter, warned on social media of an “economic nuclear winter” if the president doesn’t call a time out on his tariff policy, while Jamie Dimon, JPMorgan Chase & Co.’s chief executive officer, said it “may be disastrous in the long run.”

But Griffin, who the Bloomberg Bilionaires Index estimates has a $41.8 billion fortune, is also a Republican mega-donor. He’s given at least $100 million to pro-Republican political action committees in the last presidential cycle, data from OpenSecrets show, although none of that money went to support Trump’s campaign.

Republican lawmakers so far have largely stood behind Trump, but there is brewing opposition, including Senator Ted Cruz of Texas, who has warned of job losses and damage to the economy.  

This is not the first time Griffin has taken issue with the president’s tariffs. In early February, he called them a bad negotiation tool because they sow mistrust with allies and could dull Americans’ competitive edge.

Now, the global backlash to Trump’s higher-than-expected tariffs risks undermining U.S. influence, Griffin said. “We have led the world for 70 to 80 years,” he said. “I am really afraid of us abdicating our role of leadership for the free world. That’s the path we’re on.”