Both the stigma of being charged with a crime and the burden of a trial — including a likely need to be in the courtroom at times — would undermine the president’s abilities to carry out his duties, preventing the executive branch “from accomplishing its constitutional functions” in a way that cannot “be justified by an overriding need,” as Robert G. Dixon Jr., then the head of the Office of Legal Counsel, wrote in September 1973.
That theory — crafted by lawyers appointed by Presidents Richard M. Nixon and Bill Clinton — has been contested by some scholars. In particular, lawyers working for the special prosecutor in the Watergate case, Leon Jaworski, and the independent counsel in the Whitewater and Monica Lewinsky investigations, Kenneth Starr, maintained that the Justice Department’s interpretation was wrong and that a president could be indicted while in office.
Those who think a president can be indicted have cited a 1997 Supreme Court ruling that held that a lawsuit against Mr. Clinton could proceed while he was in office, notwithstanding the burdens that it imposed upon him. They have also pointed to the 25th Amendment, which allows a president who is disabled from performing his duties be temporarily replaced by the vice president.
But Mr. Mueller appears to have far less latitude than either of those predecessors in how he chooses to interpret the law. The regulations that Rod J. Rosenstein, the deputy attorney general, cited when appointing Mr. Mueller say that he must obey the Justice Department’s “rules, regulations, procedures, practices and policies,” and Office of Legal Counsel interpretations of the law are generally binding on the department.
Moreover, neither Mr. Jaworski nor Mr. Starr ultimately tried to indict Mr. Nixon or Mr. Clinton. Instead, as a prudential matter, they let Congress decide, through impeachment proceedings, whether to remove those presidents from office on the basis of the evidence they had helped to gather.
As for the possibility of listing Mr. Trump as an unindicted co-conspirator in court documents, Justice Department rules strongly discourage identifying people as uncharged wrongdoers “in the absence of some significant justification.” The rules, listed in the United States attorneys’ manual, do not explain what would make it necessary, but require higher-level approval to do so.
Because of those legal and those historical precedents, then, many legal analysts have assumed that even if Mr. Mueller uncovered sufficient evidence to indict Mr. Trump, he — with Mr. Rosenstein, who oversees his decisions — would most likely seek to refer the matter to Congress rather than seeking the president’s indictment, at least while he remains in office.