Everything that has happened in the Trump probe stands out against a backdrop of leniency in the Clinton investigation. While Mueller has prosecuted two Trump associates for lying to the FBI, the Obama Justice Department gave a pass to Mrs. Clinton and her subordinates, who gave the FBI misinformation about such key matters as whether Clinton understood markings in classified documents and whether her aides knew about her homebrew server system during their State Department service. Mueller’s team conducted a predawn raid at gunpoint in executing a search warrant on Paul Manafort’s home while Manafort was cooperating with congressional committees. When it came to the Clinton case, though, the Justice Department not only eschewed search warrants, or even mere subpoenas, but they never even took possession of the DNC server alleged to have been hacked by Russian operatives.

The irregularities in the Clinton-emails investigation are breathtaking: the failure to use the grand jury to compel the production of key physical evidence; the Justice Department’s collaboration with defense lawyers to restrict the FBI’s ability to pursue obvious lines of inquiry and examine digital evidence; immunity grants to suspects who should have been charged with crimes and pressured to cooperate; allowing subjects of the investigation to be present for each other’s FBI interviews and even to act as lawyers for Clinton, in violation of legal and ethical rules; Comey’s preparation of a statement exonerating Clinton months before the investigation was complete and key witnesses — including Clinton herself — were interviewed; and the shameful tarmac meeting between Obama attorney general Loretta Lynch and Mrs. Clinton’s husband just days before Mrs. Clinton sat for a perfunctory FBI interview (after which Comey announced the decision not to charge her).