Hillary Clinton isn't the first to face this. It happened just two years ago.
The office at stake wasn't 1600 Pennsylvania Avenue, but 1350 -- the D.C. mayor's office.
And the response of the media wasn't widespread condemnation as it is today.
In 2014, D.C. Mayor Vincent Gray was leading his primary challenger, Muriel Bowser. Then U.S. Attorney Ron Machen stepped in.
Just a week before early voting began, Machen accused the mayor of knowing about a shadow campaign that aided Gray's upset win four years earlier.
Despite Machen's years-long investigation, he never turned his accusations against Gray into charges; nor did his successor, who quietly brought the investigation to a close five years after it began.
Machen's actions had an impact: Gray was defeated, his reputation badly tarnished.
"My reelection was sabotaged, and District voters were duped," Gray wrote in a recent op-ed entitled "I know what it's like when law enforcement intervenes in an election. It happened to me."
Eric Holder, the former attorney general and Machen's boss at the time, defended Machen's election-eve accusations.
But now Holder is "deeply concerned" with this practice -- at least when it comes to Clinton, who he's supporting.
Last week, FBI Director James Comey sent a vague, unsolicited letter to Congress (and thereby the public) saying the FBI was revisiting its previously closed investigation into Clinton's use of a private server for emails.
President Obama weighed in, criticizing Comey without naming him. "We don't operate on incomplete information," Obama said.
Holder also rebuked the FBI director. By discussing his "personal opinions" on the eve of the election, Comey committed "a stunning breach of protocol" which "may set a dangerous precedent," Holder wrote in an op-ed.
Holder's hypocrisy is outdone by the media, led by the Washington Post.