The I.R.S. said on Thursday that its commissioner, Charles P. Rettig, had asked the inspector general who oversees tax matters to investigate how James B. Comey, the former F.B.I. director, and his deputy, Andrew G. McCabe — both perceived enemies of former President Donald J. Trump — came to be faced with rare, exhaustive audits that the agency says are supposed to be random.
“The I.R.S. has referred the matter to the Treasury Inspector…