Even assuming that the Fed is actually acting independently and not in direct response to Trump's demands for economic stimulus as a means of shielding the economy from his own policy choices, no one can deny that it at least appears that the President is getting his way. Indeed, there are two hard truths that we must accept from this recent episode: (1) no president has previously so publicly lobbied for a rate cut; and (2) it is highly unusual for the Fed to cut rates during strong expansions. The January 2001 rate cuts preceded the 2002 crash (with the NASDAQ losing 80% and the S&P losing 50%). The rate-cut in the summer of 2007 preceded the crash that cost the S&P 57%. 

While it might provide a minor (and likely brief) economic boost, long-term a rate cut will erode credibility in the Fed and undermine one of the U.S.'s most powerful institutions.