When it comes to the president's perceived enemies facing investigations, the former CIA director and former FBI director have plenty of company.

Brennan said on Wednesday he "knows nothing" of the Department of Justice investigations into himself and ex-FBI Director James Comey but slammed the probes as politically motivated.

John Ratcliffe, the C.I.A. director and a harsh critic of his Democratic-appointed predecessors, has made a criminal referral of Mr. Brennan to the F.B.I., accusing him of lying to Congress, official...