Comey himself acknowledged that: "throughout history, some presidents have decided that because 'problems' come from Justice, they should try to hold the Department close. But blurring those boundaries ultimately makes the problems worse by undermining public trust in the institutions and their work." Comey has also acknowledged that the president had the constitutional authority to fire him for any or no cause. President Trump also had the constitutional authority to order Comey to end the investigation of former national security adviser Mike Flynn. He could have pardoned Flynn, as Bush pardoned Weinberger, thus ending the Flynn investigation, as Bush ended the Iran-Contra investigation. What Trump could not do is what Nixon did: direct his aides to lie to the FBI, or commit other independent crimes. There is no evidence that Trump did that.