For a moment on Wednesday, it looked like President Donald Trump would finally attempt the improbable and fire Federal Reserve Chair Jerome Powell.

The president prefers low interest rates. But the Federal Reserve Act protects the Fed chair's removal. Long-term rates are set by financial markets and sensitive to inflation expectations.

Investors, not the Fed, control the interest rates that matter most to businesses and consumers. They might demand higher returns if the central bank’s independence comes into question.