We’re in intermission now, after Attorney General William Barr’s two letters about the report from special counsel Robert Mueller. We still don’t know much more than we did when Mueller delivered his report to Barr on March 22. But next time we hear about its contents, President Donald Trump will likely be less pleased than he was with Barr’s initial performance.

Barr asserts the report doesn’t establish collusion between Trump’s presidential campaign and Russia and doesn’t justify prosecution of Trump for obstruction of justice. Even people who didn’t foresee those opinions shouldn’t be surprised, since both collusion — or conspiracy, for criminal purposes — and obstruction are difficult to prove in a legal sense.

It is no accident that throughout the Mueller investigation, Trump protested with a single complaint: “No collusion! No collusion!” Trump would have known — his lawyers certainly did — that of all the charges swirling around him, collusion would be the hardest to establish. Let no one underestimate the man’s shrewdness.

Trump would have known — his lawyers certainly did — that of all the charges swirling around him, collusion would be the hardest to establish.

After Barr’s first letter, Trump quickly added, “No obstruction!” to his repertoire. He hasn’t emphasized it, since Barr noted that Mueller didn’t actually exonerate Trump of the charge. But obstruction is another backbreaker of a crime to establish.

It requires a showing of corrupt intent, unless there’s a threat involved. That kind of intent is exceedingly hard to establish in a president.

No Collusion, No Obstruction, Complete and Total EXONERATION. KEEP AMERICA GREAT! — Donald J. Trump (@realDonaldTrump) March 24, 2019

If most people, for example, try to persuade a federal prosecutor to drop a case, the action creates a suspicion of corrupt intent. But a president, as the nation’s chief federal law enforcement officer, has extremely broad authority over federal prosecutions and investigations. So, what does it take to establish that the exercise of this authority was corrupt?

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Our model for presidential obstruction of justice comes from Watergate, in which audio tapes of Oval Office conversations made by President Richard M. Nixon himself provided the final evidence of his having obstructed the Watergate investigation. Less remembered is that until this evidence emerged, two years after the Watergate break-in, it was by no means certain that an obstruction case could be established.

A team of men working for Nixon’s re-election campaign broke into the Democratic National Committee headquarters in Washington’s Watergate building complex in June of 1972. But not until July, 1974, did the House Judiciary Committee, in its first draft article of impeachment, officially accuse Nixon of “using the powers of his high office” to take actions “designed to delay, impede, and obstruct” the burglary investigation and “cover up, conceal, and protect those responsible.”

A string of serious miscalculations ultimately brought the necessary evidence of obstruction to light: Nixon’s decision to manage his own defense; his determination not to grant immunity to White House counsel John Dean and his choice to preserve the audio tapes he had made of his Oval Office conversations.

After the existence of the tapes was revealed in July of 1973, Nixon debated with his inner circle whether to destroy them. True, once the Senate Watergate committee announced its intention to seek the tapes, destroying them would arguably have constituted criminal destruction of evidence. But Nixon seemed politically strong enough to withstand the uproar.

If Nixon had destroyed the tapes, we would never have heard the recording on which Nixon said, just after the Watergate burglary — in his own voice, no doubt about it — that the CIA should tell the FBI to lay off its investigation of the break-in.

Many people had long assumed that Nixon might have said something like this. But the “smoking gun” tape revealed it, breaking the back of support for Nixon in the country.

Many people had long assumed that Nixon might have said something like this. But the “smoking gun” tape revealed it, breaking the back of support for Nixon in the country. It persuaded even previously loyal Republican senators that Nixon could not and should not be saved. Watergate Special Prosecutor Leon Jaworski later said that if it hadn’t been for the tape, Nixon might have survived Watergate.

In other words, establishing obstruction by a president is a hard job. Barr’s letter has now made it harder in Trump’s case: It suggested that because Mueller’s report hadn’t established collusion between the Trump campaign and Russia, there was no underlying crime that would have given Trump a motive to obstruct Mueller’s investigation — as Nixon had done in Watergate. But that’s not true. There are lots of reasons, apart from underlying criminality, to try to obstruct an investigation.

For instance, conspiracy or no conspiracy, we know these things: The Russian government intended to help Trump win the 2016 election. The Russians did help Trump win the 2016 election. Trump cannot bring himself to admit that the Russians helped him win the 2016 election. For Trump, that may be enough of a motive to try to obstruct an investigation.

But in contrast with Nixon’s White House, Trump’s White House is unlikely to produce a smoking gun tape. Watergate has taught presidents some lessons — like the inadvisability of a taping system that turns itself on whenever the president starts speaking in the Oval Office.

Even if Trump had a motive for obstruction and there was evidence that might be viewed as a smoking gun, by now Trump would probably have tweeted it to his base — and the general public.

When we’re dealing with normal human psychology, this kind of public display of potentially corrupt motives would not happen. Normally, corrupt intent is secret and ashamed. It hides a deed — illegal, embarrassing, evil — that it doesn’t dare expose openly.

Trump, however, has regularly committed potentially obstructive acts out in the open. In a person with normal psychology, Trump’s behavior would indicate that he had nothing to hide. But nothing about this presidency is normal.

In a person with normal psychology, Trump’s behavior would indicate that he had nothing to hide. But nothing about this presidency is normal.

Whatever comes next, Barr’s first letter has already delivered a powerful lesson about law and politics in America. We have a settled habit of displacing political judgments with legal judgments. When we’re faced with questions about whether a politician’s actions are morally justified, for example, we instead ask whether he or she has committed a crime.

This is a useful habit. It narrows the scope of our disagreements. It channels political passions in ways that make them less destructive.

But it means that we often miss the target. In Watergate, focusing on criminal behavior succeeded in removing a president who had offended not just laws but values even deeper than laws. More often, though, the displacement keeps us from addressing the problems we mean to target.

According to Barr’s first letter, we don’t have the evidence to establish that the president conspired with a foreign power and, by a narrower margin, don’t have the evidence to establish that he obstructed justice. Neither of these conclusions helps us judge whether Trump has committed impeachable offenses. Let alone whether he is unfit to hold his office.

So, we now move to round two: the actual Mueller report and the questions it did not ask, but, instead, distributed to other investigators throughout the country. Many of these questions will also miss the target. Some, though, will be less difficult than conspiracy and obstruction — for example, campaign finance violations, tax offenses and insurance and ordinary old commercial fraud. We’ll descend into territory in which Trump may not fare well.

It’s about time for us to return to our seats.