Here is an excellent 2018 Lawfare essay on the memos regarding indicting a president.

[Grasswire2]

By Walter Dellenger:


Walter Dellinger is a partner at the law firm of O’Melveny & Myers and the Douglas Maggs Emeritus Professor of Law at Duke University. He was assistant attorney general and head of the Office of Legal Counsel from 1993 to 1996 and acting solicitor general of the United States from 1996 to 1997.


[link:https://www.lawfareblog.com/indicting-president-not-foreclosed-complex-history|

Can a sitting president be indicted? Often, in answering this question, commentators point to Office of Legal Counsel (OLC) opinions answering in the contrary. To whatever extent the writer agrees or disagrees with the opinions’ conclusion, the government’s position on the matter is usually presented as a long-standing and clear “no.”

The reality is more complicated. The United States has addressed this question six times in both internal memos and briefs filed in litigation. And a review of these documents shows that it is far from clear what criminal prosecution steps are (or should be) precluded—and that there is no “longstanding policy” against indictment of the president. Consider the 1973 OLC memo stating that a sitting president should not be indicted. Far from being authoritative, it was essentially repudiated within months by the Justice Department in the United States’ filing in the Supreme Court in United States v. Nixon.

Likewise, the most recent opinion—an OLC memo written in 2000—includes brief statements that a sitting president should not be indicted even if all further proceedings are postponed. But far from being definitive, this is a matter that could be reconsidered by the department. Moreover, of course, OLC opinions are not binding on state prosecutors (though state charges could raise federalism questions as well). The complex history of criminal proceedings against presidents and vice presidents suggests that these issues are not foreclosed.

Perhaps the most important point that emerges from a review of all the opinions is this: only once has the United States addressed the question of whether a president can be an unindicted co-conspirator. The conclusion was an unequivocal yes. Richard Nixon was so named in the Watergate indictment, and that inclusion was sustained by Judge John Sirica and defended by the United States in United States v. Nixon. (The Supreme Court did not resolve the question.) No department opinion or filing has ever contradicted that position. The fact that it is permissible to name a sitting president as unindicted co-conspirator, moreover, tends significantly to undermine the only argument against indicting a sitting president.

much more at link.