Director James Comey has put himself and the FBI squarely in the middle of the most volatile presidential election in modern history, and now he must take what comes with that.

By “updating” Congress on the existence of e-mails that might be related to the closed investigation of Hillary Clinton’s private server — e-mails the bureau had neither seen nor determined the significance of, Comey has left himself open to charges that he was deliberately exerting influence that could interfere with an election in its closing days. He went against long-standing Justice Department policy to do so, even after being warned by department lawyers.

Comey’s action threatens the integrity of one of the nation’s top law enforcement institutions, adding to the foment about whether this election is “rigged.” Since issuing an overly cryptic, three-paragraph letter to Congress, Comey has remained regrettably silent, allowing Republican spin to fill the void. It should be remembered that Comey also broke with protocol in July, when he concluded that there would be no charges after an exhaustive investigation into Clinton’s e-mail activity, and that no reasonable prosecutor would do differently. Then he added his own opinion that Clinton and her top aides had been “extremely careless,” thus effectively tainting any exoneration even though he found no evidence of wrongdoing.

Richard Painter, a University of Minnesota law professor who was chief ethics lawyer for the George W. Bush White House, is right when he says that unnecessarily publicizing pending investigations during an election is an abuse of power and a precedent that cannot be allowed to stand. Painter has filed complaints with the Office of Special Counsel, which investigates violations of the Hatch Act, a federal law that prohibits officials from interfering in elections, and with the Office of Government Ethics.

To understand how unusual Comey’s actions are, consider that typically the FBI doesn’t acknowledge the existence of an investigation, let alone give updates. On Sunday, the Clinton campaign released a letter signed by nearly 100 former prosecutors and senior Justice Department officials from both parties criticizing Comey for the unusual move.

Having opened up this mess, Comey now is obliged to shed more daylight on what the bureau knows, when it knew it and why he felt such an overwhelming need to go to Congress. Part of the blame, undoubtedly, lies with a Congress that has pushed him relentlessly for information. Senate Judiciary Chairman Chuck Grassley, R-Iowa, complained bitterly in September that Comey had a “vice grip” on details of the closed investigation and demanded their release. Grassley even went so far as to say that Comey should have negotiated restrictions with his committee in advance.

On Monday, Grassley said in a letter to Comey that his disclosure to Congress had so little information that it was unfair to Clinton and the public. Grassley has asked that Comey respond to written questions that would provide needed details no later than Nov. 4. That is too late. Grassley should immediately call on Comey to testify publicly. And Minnesota’s representatives on the committee, Democratic Sens. Amy Klobuchar and Al Franken, should push for emergency testimony so that voters can know what they are dealing with as this tumultuous election heads into its final week.