Removing Rosenstein and replacing him with a DAG who is at the very least more sympathetic to Trump could have drastic repercussions for the investigation. The new DAG could burden the special counsel with a requirement to provide an explanation for every move he makes and then decide that they aren’t necessary or appropriate. In fact, because Mueller is required to provide the DAG with at least three days’ notice in advance of any “significant event” in the investigation, she would have plenty of time to intervene and challenge Mueller’s actions (and a less scrupulous DAG could even leak Mueller’s plans to the White House or others). A new DAG would even have the ultimate, er, trump card: She could decide at some point that the investigation should not even continue at all.
Of course, any attempt to override a decision by Mueller would need to be reported and justified to Congress. However, given the increased clamor of some GOP members and right-leaning media outlets against the Mueller investigation, a DAG’s rationale for pushing back on Mueller’s investigation would find a receptive audience in some circles, including on the Hill. The situation is delicate, and the DAG has a powerful platform to shift the balance of power against the investigation. Imagine the next DAG simply expressing doubts about Mueller in testifying before Congress, instead of projecting the level of confidence Rosenstein expressed last week before the House Judiciary Committee. Those are important moments in the life of this investigation, and a DAG not fully committed to the rule of law but to insulating the president and the White House from political and legal accountability could wreak havoc.