President Donald Trump’s effort to force the Department of Justice and the FBI to disclose key elements of the Mueller probe (what he's called "Spygate") is neither a new affront to the department’s or the agency’s independence, nor a particularly effective one.

What President Trump has done in public via Twitter and now in a well-publicized meeting, President Richard Nixon had previously done in private by obtaining secret grand jury information from the Assistant Attorney General about the ongoing investigation of his White House aides and his presidential campaign.

Nixon’s efforts, however, could not save his White House and campaign aides from criminal convictions, nor would it have saved him from impeachment had he not chosen to resign. President Trump’s ham-handed efforts will fare no better.

That’s not to say that Trump’s public demand that the Department of Justice turn over information about the FBI’s confidential sources and methods in the Russia investigation hasn’t rightly alarmed law enforcement and intelligence officials. Allowing the president to exercise his authority to compel prosecutors to disclose information about the investigation of those close to him is not only a dangerous precedent but also a potential abuse of power.

But, Associate Attorney General Rod Rosenstein and FBI Director Christopher Wray will have realized that any classified information about Robert Mueller’s investigation that they shared with congressional Republicans or the White House would be almost instantaneously leaked to the public. Once leaked, the subjects of the investigation would gain an unprecedented advantage in planning their defense by discovering at least a little about what prosecutors have found so far. ...