Deputy Attorney General Rod J. Rosenstein speaks during a news conference in July at the Justice Department in Washington. (Evan Vucci/AP)
Opinion writer

As of this moment, it is unclear if Deputy Attorney General Rod J. Rosenstein is going to remain in office until the midterms, resign or be fired. If Republicans don’t retain the Senate, there is no telling who would replace him after that. The terms of his departure matter quite a lot.

An impressive cross-section of lawyers, ex-governors, Republican loyalists and scholars wrote to Rosenstein this week, essentially pleading with him to stay to continue oversight of the investigation by special counsel Robert S. Mueller III. The letter stated:

The stakes for the country are paramount in continuing to ensure that the Mueller and related investigations are allowed to continue uninterrupted to their conclusion without any outside interference. If you leave, the American people have no guarantees that those investigations will remain independent and free from intervention or restrictions in the future.

The American people are entitled to know the results of the Mueller investigation and the handling of any report from Special Counsel Mueller is currently to be determined by you. It is essential for the good of the country that you stay at your post and continue to protect the Mueller and related investigations from any outside interference. We strongly urge you not to resign, and should your resignation be demanded, to decline.

The signers implore Rosenstein to recall that the lawyers “who were fired in the Saturday Night Massacre were celebrated at the time as heroes, a judgment vindicated by history.”

One of the signers, Fred Wertheimer of Democracy 21, explains to me, “The diverse groups and concerned citizens sending this letter believe it is essential for Deputy Attorney General Rosenstein to stay in his job and continue to protect the Mueller investigation.” He argues, “The serious dangers for the country and the rule of law that lie ahead if Rosenstein leaves his position already can be seen in the call by President Trump’s lawyer to ‘pause’ the [Russia] investigation if Rosenstein is gone.”

Another signatory, Laurence Tribe, tells me that how Rosenstein leaves is important, too. “Rod Rosenstein has been a vital defender of our constitutional republic. He is likely to face enormous pressure to cut and run,” he says. “But the man whose dedication to law I have long admired is better than that. If he is to be displaced by a partisan hack, he must make clear that it’s the president who is shoving him aside.”

And what’s the difference if he quits or gets fired? First, there are the political and legal implications for Trump; if Trump fires Rosenstein, he will need to convince Mueller that this isn’t one more act in a pattern of obstruction of justice designed to sink the Russia probe. Second, it matters from a statutory standpoint in determining how and whether Trump can replace Rosenstein without Senate confirmation. Tribe and Norman Eisen, writing today in The Post, argue that under the Federal Vacancies Reform Act, Rosenstein cannot be replaced by a previously Senate-confirmed official (e.g. Education Secretary Betsy DeVos) if Trump fires Rosenstein:

The Federal Vacancies Reform Act gives the president the power to name any other Senate-confirmed person as a temporary replacement in the event that the holder of a position “dies, resigns, or is otherwise unable to perform” the functions of the office. …

In 1999, the Justice Department’s Office of Legal Counsel (OLC) suggested that the legislative history of the statute implies that a firing might constitute “inability to perform the functions and duties of the office.” But the OLC is known for protecting the prerogatives of the president, and in our view, that interpretation runs counter to the language and purpose of the statute itself. The OLC’s opinions are not law and, in this case, we think the OLC is wrong.

In short, it’s worth a try to force Trump to fire Rosenstein if and when he goes, for no other reason that it provides some protection against automatic installation of a presidential flunky.

Rosenstein, who purportedly wanted to negotiate friendly terms of departure, should wise up. Trump will say whatever mean things he wants about Rosenstein no matter what deal they agree to. Rosenstein should at this critical time worry less about how his departure will be choreographed and more about giving Mueller some protection, if only temporarily.