U.S. President Donald Trump's attacks on the Federal Reserve have broken one set of precedents, his talk of stacking the central bank with political allies has strained another, and his on-again, off-again tariff threats have made the economic outlook harder than ever to predict.

While the Fed may well find reason to cut interest rates in recent weak job and inflation readings, doing so could also put a safety net under Trump policies that, to the eyes of many policymakers, have to date done more harm than good.

"There is a kind of feed the beast aspect to it," said former Fed vice chair Alan Blinder. "Among the many things the Fed has to take as given is trade policy. And if in fact trade policy is going to push the economy into a slump, that is a reason to cut interest rates. ... If the Fed comes in to bail him out you encourage bad behavior."