On Monday morning, Trump again lashed out at Powell on his Truth Social, calling the Fed chair "a major loser" and demanding he lower interest rates "NOW." The stock market, which had begun to calm from tariff-induced panic, quickly plunged, with the S&P 500 closing down 2.3%.

In fact, there’s a long history of presidents putting pressure on Fed chiefs to cut interest rates. But President Trump’s public harangues to fire Jerome Powell are unprecedented and could create more difficulties.