#TrumpVsPowell President Trump revived a long-standing threat to Jerome H. Powell this week when he accused the Federal Reserve chairman of "playing politics" and moving too slowly to reduce interest rates. But privately, according to people close to Mr. Trump, the president has been aware for months that an attempt to oust Mr. Powell could inject greater volatility into nervous financial markets.

Investors are already on edge after a period of turmoil due to the snap tariffs that the administration announced this month. Undermining the political independence of the Fed, which is seen as critical on Wall Street, could risk much more significant financial panic.