The first OLC memo was issued on September 26, 1973, not long before the October 20 “Saturday Night Massacre,” in which Nixon directed officials of the Justice Department to fire special prosecutor Archibald Cox, and the top two Justice officials resigned, leaving the dirty work to then-Solicitor General Robert Bork.

That memo considers the Constitution’s text and finds no answer. It says, correctly, that there is no “airtight separation of powers, but rather … a system of checks and balances, or blending the three powers.” The Constitution provides very limited immunities for members of Congress and none for the president. The impeachment clause says that any official impeached can be tried—at least, but not clearly only, after removal. The debates during the framing and ratification of the Constitution suggest that the president is subject to laws like any citizen, but never discuss prosecution in office. During the trials of Aaron Burr, Chief Justice John Marshall had insisted that Thomas Jefferson was subject to subpoena—but also that as president he could refuse to attend court in person, and could withhold some evidence.

Left with no clear sources, the Justice Department lawyers asked what answer would best serve the nation. An indictment in office would besmirch the “symbolic head of the nation.” In addition, “only the president can receive and continuously discharge the popular mandate expressed quadrennially in the presidential election,” making an indictment or trial “politically and constitutionally a traumatic event.” Impeachment is the first line of defense against presidential misconduct, the author noted. “This would suggest strongly that … criminal proceedings against a President in office should not go beyond a point” that they would effectively remove a president, and thus become a short-cut for impeachment.

In other words, an indictment of a serving president wouldn’t be a good idea.

The Bork memo, issued just 11 days later, assumes that those arguments are valid, and shows that they do not apply to the vice president. On a number of occasions, Bork noted, “the nation lacked a Vice President, and yet suffered no ill consequences.” Indeed, the third vice president, Aaron Burr of evil fame, served the last year of his term under indictment by two states, New York and New Jersey. The president has “complete power over the execution of the laws,” making a prosecution of himself by himself absurd, Bork argued; a “Vice President, of course, has no power either to control prosecutions or to grant pardons.”

Twenty-seven years later, OLC reexamined the question. By this time, there had been major Court decisions, all indicating that the president was not immune to the reach of the justice system. United States v. Nixon required the president to turn over his tapes to a court seeking to use them in a criminal case against other defendants; Clinton v. Jones held that Bill Clinton could not stay a sexual-harassment lawsuit against him until leaving office. In addition, the country had lived through its second presidential impeachment and Senate acquittal. Did the Court cases change the analysis? No, said the OLC lawyers. “The Framers considered who should possess the extraordinary power of deciding whether to initiate a proceeding that could remove the President … and placed that responsibility in the elected officials of Congress. It would be inconsistent with that carefully considered judgment to permit an unelected grand jury and prosecutor effectively to ‘remove’ a President by bringing criminal charges against him while he remains in office.”