We are not saying that the FBI should be barred from investigating a president who appears to be a Manchurian candidate, but the situation requires special guidance. The lines between a Manchurian candidate, a president engaged in quid pro quo foreign-policy bargaining that is possibly corrupt, and the very large discretionary control that presidents have to conduct U.S. foreign policy are not always easy to discern. The decision to open a counterintelligence investigation of the president is so consequential for the nation (and the FBI), and so politically fraught, that it should not be made without much clearer guidance. It also should not be made by the FBI alone. FBI leadership wisely realized this truth, even without specific guidance, because they quickly briefed the acting attorney general and relevant congressional leaders. Such briefings should be mandatory—both for the FBI’s sake, and to ensure that Justice Department leaders do not eschew their responsibilities.

Horowitz additionally noted that the FBI had no policy on whether to give notice to campaigns, like Trump’s, that are subject to investigation. According to Horowitz, the discretionary call not to inform the Trump campaign was made by an assistant director of an FBI division, who concluded without any guidance that such notice might prevent the FBI from “finding the truth.” But this decision poses a huge legitimacy risk to the bureau, because the failure to notify can later be construed as evidence of political motivation. The FBI needs a clear policy and procedures on when and how it informs presidential campaigns about investigations.

Horowitz identified other important gaps in the standing FBI guidance about investigations related to political campaigns. As he set out in his report and his testimony to the Senate, the use of confidential human sources for “consensually monitoring” individuals affiliated with the Trump campaign, including an official who was not a subject of the investigation, was “permitted under Department and FBI policy because their use was not for the sole purpose of monitoring activities protected by the First Amendment.” However, he noted that the FBI rules allow agents to seek approval of this kind of intrusive investigative technique from only a first-level supervisor, without any requirement that the FBI notify senior Justice Department officials. Horowitz recommended a requirement that there be “consultation, at a minimum.” The department should consider a rule requiring both notice and approval in cases involving politicians and campaigns.