House Intelligence Committee Chairman Devin Nunes (R-Calif.), right, and Rep. Peter King (R-N.Y.). (Chip Somodevilla/Getty Images)

Sheldon Whitehouse, a Democrat, represents Rhode Island in the Senate.

As the president’s and House Intelligence Committee Chairman Devin Nunes’s recent actions underscore, there is a concerted effort to undermine special counsel Robert S. Mueller III’s investigation into Russian meddling in U.S. elections and possible obstruction of justice. The FBI and the Justice Department have become targets of dirty tricks. The unfair charges are gutter politics: trashing American institutions to protect a president from the due course of the law.

I have served as Rhode Island’s U.S. attorney, working closely with the FBI and other federal law enforcement agencies. Nothing about the Justice Department or the FBI merits the kind of smear campaign ramping up on the far right.

Agents and prosecutors are human. They are fallible and make mistakes. That’s why there are so many cross-checks and sign-offs in these organizations and in the broader judicial system. As FBI director, James B. Comey made a terrible mistake in the Clinton email investigation when he went rogue and violated a long-honored rule against divulging derogatory information about an uncharged person. But I ascribe it to an overly assiduous concern for his own reputation for fairness, not to any corrupt intent. The notion that the FBI is corrupt or politicized is being trafficked for purposes far more corrupt — and far more baldly political — than the FBI could ever be.

Critics also charge that then-FBI Deputy Director Andrew McCabe was too biased to oversee the Clinton investigation. They claim that because his wife, a former Virginia state Senate candidate, was assisted financially by a political organization controlled by then-Virginia Gov. Terry McAuliffe, a Clinton ally, McCabe should have immediately recused himself. In evaluating that purported conflict of interest, remember that Supreme Court Justice Clarence Thomas’s wife is a paid advocate for right-wing policies her husband supports from the bench. That we tolerate that from a final decider in the judicial process gives context to the claims levied against someone participating in investigative decisions at the earliest stage of the process, surrounded by checks and balances. Furthermore, McCabe, in line with FBI guidelines, disclosed the conflict. If McCabe’s later participation in the Clinton investigation was inappropriate, inspectors general can and will look into it; but litigating this on conservative talk shows looks like a smear campaign, not responsible oversight.

That campaign has turned to a shady practice: selective declassification. It is possible to create a false narrative from a trove of classified information, either by selectively declassifying misleading tidbits of material or by suggesting misdeeds that can’t be disproved without revealing classified information. The shield of classification becomes a sword of deception.

This is the technique of the smear campaign against former British intelligence officer Christopher Steele and the “dossier” he compiled outlining Donald Trump’s ties to Russian officials and business figures. Republicans referred Steele to the Justice Department for criminal investigation based on classified information obtained from the FBI. That makes it hard to rebut publicly.

The memo from Nunes (R-Calif.) uses the same technique in alleging abuses of power by the FBI in the Russia investigation. Specifically, the memo accuses the FBI of misleading the Foreign Intelligence Surveillance Act court in applying for surveillance warrants. It’s a dirty trick, and a signal of the desperate measures involved. The FISA court approval process is shrouded in secrecy, and for good reason: Our intelligence services need to carefully protect their sources and their methods. FISA court applications and approvals may contain information about both. Releasing FISA-related information, as the Intelligence Committee Republicans have done, threatens serious damage to our intelligence collection and endangers national security. Yet Republicans have stampeded right through stern objections and warnings from senior national security officials — another sign of the GOP’s desperation.

It’s not as if this was Republicans’ only way to use Congress’s oversight powers. There are inspectors general, privacy boards, professional responsibility reviewers and congressional oversight committees. In the early stages, working in those channels would keep the secrets. Once a conclusion about misdeeds was reached, a public report — with or without a classified annex — could be produced; ideally a bipartisan one. The GOP’s unprecedented tactics only make sense if the point of the effort is to influence the public debate.

FBI agents and federal prosecutors make hard decisions and often take considerable risk. They sometimes take on very popular targets or have to let unpopular targets go because that is what justice requires. The hours can be arduous, particularly on tasks such as surveillance; and the quality of their work can have actual life-or-death consequences. Any agent who has been cross-examined at trial has learned the importance of carefully backstopped case preparation and being sure to get it right. The far right’s smear campaign is trying to undermine the legitimacy of an investigation that appears to be bearing down on the president. The country deserves better.