Alan Greenspan, Ben Bernanke, Janet Yellen and other former officials from Democratic and Republican administrations rushed to defend Powell and the Fed’s ability to set monetary policy free from political influence, calling the investigation “an unprecedented attempt to use prosecutorial attacks to undermine that independence.”

Jamie Dimon on Tuesday defended the Federal Reserve after it was subpoenaed by the Justice Department, saying that “anything that chips away” at the central bank’s independence “is not a good idea.”