I've made no secret of my belief that the appointment of Rosenstein as DAG was part of a corrupt deal Jeff Sessions made with Chuck Schumer and possibly some Republican Senators to get confirmed as AG. Fox News provided a handy reprise of Rosenstein's first days as DAG:
Fox News Research
Rosenstein's First Days at DOJ:
•4/25: Confirmed 94-6
•5/9: Wrote memo outlining concerns w/ Comey’s conduct
•5/9: Trump fired Comey citing Rosenstein memo
•5/16: Reportedly raised idea of recording Trump, invoking 25th amend. to remove Trump
•5/17: Appointed Mueller
166 8:48 AM - Sep 24, 2018
'Nuff said--his conflicts, stonewalling, and protection of the Deep State/Swamp have been well documented.
At the time Barr was nominated, it was widely reported that Barr had made a condition for his acceptance the ability to name his own DAG. While it was added that he had withdrawn that condition, the suspicion remains strong that one of his earlier acts as AG would have been to fire Rosenstein, and that Rosenstein--knowing his days were numbered--decided to leave ahead of the broom in the hope of salvaging his reputation. Such as it is.
This development should greatly strengthen Barr's hand at DoJ--as witness his reported condition--especially in cleaning out corrupt career players. It should also give him a trustworthy aid to oversee DoJ while Barr personally grapples with the Russia Hoax.