President Trump is being accused of “obstruction of justice” because of a conversation that he may have had with former FBI Director James Comey. According to the news stories, Trump may have asked Comey to lay off his former National Security advisor, Michael Flynn. In this post I want to briefly examine the legal doctrine of obstruction of justice.

To begin, a basic principle of American criminal law is that the line between what’s lawful and what’s unlawful needs to be clear so we will know, in advance, what conduct might land us in a prison cell. That’s the gist behind the constitutional prohibition of ex post facto laws. Laws with vague terms raise the same danger. When laws are vague, police and prosecutors can abuse their power and trap people. And that’s the danger with a catch-all doctrine such as “obstruction of justice.”

“Obstruction” has sometimes been defined by the authorities as almost any action that “impedes” an investigation. Invoking your constitutional right to silence, your right to speak with an attorney, or the attorney-client privilege are sometimes deemed “obstruction.” Don’t the courts restrain those abuses? Yes, sometimes they do. I’m presently editing a book of Judge Alex Kozinski’s legal opinions. One case, United States v. Caldwell, touches on this subject. Here is Judge Kozinski:

Under the government’s theory, a husband who asks his wife to buy him a radar detector would be a felon — punishable by up to five years in prison and a fine of $10,000 — because their actions would obstruct the government function of catching speeders. So would a person who witnesses a crime and suggests to another witness (with no hint of threat) that they not tell the police anything unless specifically asked about it​.So would the executives of a business that competes with a government-run enterprise and lowers its prices to siphon off the government’s customers. So would co-owners of land who refuse to sell it for use as a military base, forcing the government to go to the extra trouble of condemning it. So would have Elliot Richardson and William Ruckelshaus, had they agreed with each other to quit if asked by President Nixon to fire Archibald Cox. The federal government does lots of things, more and more every year, and many things private parties do can get in the government’s way. It can’t be that each such action is automatically a felony.

I should note that when James Comey served as a prosecutor in New York, he pursued Martha Stewart and went so far as to say that her assertion of innocence was itself a violation of the law! When Comey worked as assistant attorney general, he also took a dangerously expansive view of what he considered “uncooperative” conduct by business firms. He expected lawyers for business firms to act as deputies for the federal government, which raised constitutional problems—especially for employees who were unaware of the legal minefield all around them during a purported “internal” investigation.

Let’s also consider how the doctrine might work within the government itself. Say a rookie cop busts a homeless man named Al, for possession of heroin. Al is street wise so he offers to become a snitch if his charge is dropped. Al says he was using heroin with the governor just the day before and that the governor told him that he kept a stash of other drugs in his desk at the mansion. The rookie thinks this is a huge deal and proposes to use Al in a sting operation against the governor. The police captain rejects the proposal and tells the rookie to forget the whole thing because it’s a made up story. Has the captain obstructed the investigation or exercised appropriate supervision?

Another example. Let’s say 50 FBI agents are working on the Russia investigation (improper, possibly illegal, actions involving Mr. Trump or others working on his campaign). One agent is convinced that Mr. Trump is a traitor, taking bribes from Putin, and other illegal acts. He proposes grand jury subpoenas for Mr. and Mrs. Trump so that they can be questioned under oath right away. Only his FBI supervisor rejects the idea. Has the FBI supervisor obstructed justice or exercised sound discretion?

One important difference, of course, is that neither the police captain nor the FBI supervisor, were targets (or around the targets) of the underlying investigation. Repeat: That is an important difference. The main point of this post is simply to caution against wild and vague claims of “obstruction of justice.” Legal rights should never be considered “obstruction.” When judges, or prosecutors, or law enforcement supervisors restrain overzealous subordinates, that should not be considered “obstruction.” Mr. Trump is not above the law, but investigators must also respect the law as they go about their work.