Shortly after Robert S. Mueller III was appointed to investigate possible coordination between President Trump’s campaign and the Kremlin, he was drawn into a tense standoff in which Deputy Attorney General Rod J. Rosenstein and then-acting FBI director Andrew McCabe each urged the other to step aside from the case, according to people familiar with the matter.
https://www.washingtonpost.com/world/national-security/rosenstein-mccabe-feud-dates-back-to-angry-standoff-in-front-of-mueller/2018/10/10/8a7e99fe-ccac-11e8-a3e6-44daa3d35ede_story.html?noredirect=on