President Donald Trump has been saying for 18 months that he wanted to fire Attorney General Jeff Sessions. He’s been saying for 18 months that he thought Sessions was disloyal for having recused himself from the Russia investigation and for having given day-to-day control over the investigation to the deputy attorney general, Rod Rosenstein. And, of course, Trump has been saying for 18 months that he wanted an attorney general who was personally loyal to him, in the same way the late Roy Cohn was a loyal legal pit bull.Why is anyone surprised that he’s now done what he said he was going to do? Yesterday, less than 24 hours after the midterm polls closed, Trump requested and received the attorney general’s resignation and appointed Matthew Whitaker, the chief of staff in the Department of Justice, as his interim replacement, pending the nomination and confirmation of Sessions’s successor. The only surprise is the timing—Trump moved far more rapidly than anyone might have anticipated. But the end result was, by any measure, a foregone conclusion.What does this all mean for the investigation being led by Special Counsel Robert Mueller, and what can we expect going forward?

First, and perhaps counterintuitively, we can expect a period of calm. Whitaker’s first move as acting attorney general is unlikely to be firing the special counsel. Indeed, we might actually hope that Whitaker proceeds cautiously and with some sense of history—loyalist though he may be, he likely does not want to be remembered as the second coming of Robert Bork, who is known for his role as the executioner in Richard Nixon’s Saturday Night Massacre. And given that there are doubts as to the constitutionality of his appointment, Whitaker will be wise to act with prudence.More importantly, as a matter of strategy, Mueller has no reason to precipitate a crisis. As in all matters of high political moment, the ultimate battle will play out in the court of public opinion and in the halls of Congress—and Mueller knows he will be better positioned if Whitaker fires, in effect, the first shot.Second, when and if Whitaker acts, he is unlikely to do so in an overt or politically aggressive way. There are many steps far short of shutting down the investigation that he can take to hamper Mueller’s efforts. Imagine, if you will, that Whitaker simply transfers some of the assigned FBI agents to other, “more important” tasks, or if he rejects a request from Mueller to investigate a particular area of inquiry. Those concerned with the integrity of the investigation need to be on guard for these types of more subtle obstructions, which are far more plausible than grosser efforts.

Third, we should pay close attention to congressional reaction, especially in the Republican Senate. Trump was no doubt emboldened by his belief that the Republican gains in the Senate insulate him from scrutiny. We will see if that is so.

Recall that Senator Lindsey Graham once said there would be “hell to pay” if Sessions were fired. And he also pledged solemnly that he would do everything in his power to ensure that the Mueller investigation is not interfered with. Now is the time when Graham’s bona fides, and those of his colleagues, will be tested. If congressional Republicans are truly serious, they should, for example, take up the bipartisan proposal to limit the president’s removal powers for a special counsel.

And finally, we should remember that the Mueller investigation is not the be-all and end-all of the criminal-investigative universe. By now, it is well known that large fractions of the investigation have been hived off to traditional offices of the Department of Justice—places like the U.S. Attorney’s Office in the Southern District of New York and the Eastern District of Virginia. Whatever bureaucratic games Whitaker might be able to play with the special-purpose Mueller investigation are much less effective when applied to preexisting federal offices.

So, there is every reason to think that many (if not all) of the aspects of the Mueller investigation either have been or would be transferred to other parts of the Department of Justice. It seems clear, for example, that the Southern District of New York is already investigating the president’s finances, and it would be a bold act indeed for the acting attorney general to try to shut down that investigation as well.Nor could he be confident that his actions would succeed. As has also been reported, the state authorities in New York are likewise conducting their own investigation, and the course of their efforts is beyond any influence of Whitaker.The president’s actions were a bold and aggressive move that smacks both of confidence and of concern. While it will not go down in history as the “Wednesday Afternoon Hissy Fit,” there are some real grounds for hoping that it was not a “massacre” and that the ultimate course of the presidential investigation will not be significantly altered.