This article first appeared on the blog Impeachable Offenses?

The villagers are despondent. Helpless against the ogre in the white castle looming over their town, they hired Sir Robert, peerless paladin of republican virtue, and sent him forth against the monster. After a two-year quest, every hint and rumor of which was followed breathlessly by the quaking townspeople, Sir Robert has returned. But he comes not with the ogre’s severed head hanging from his saddlebow, but with a long parchment that says, “The creature in the white palace is indeed a bad fellow, certainly not better and indeed somewhat worse than you knew him to be when you selected him to live there. What you do about that is now up to you.”

Upon reading this, the scales fell from the villagers’ eyes. Sir Robert now stood before them, revealed not as a knight in glittering plate armor with pennon flying from his lance, but as what he had been all along: a grave, punctilious, honest lawyer. Sir Robert had done what he was tasked to do, neither more nor less. And then, in their disillusionment, those villagers most wroth against the ogre wailed and rent their garments and covered their heads with ashes.

Robert Mueller was never going to save us from Donald Trump. He was certainly never going to indict a sitting president of the United States. Indeed, given the narrow scope of Mueller’s charge—to investigate “any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump” and any “matters that arose or may arise directly from the investigation”—uncovering evidence beyond a reasonable doubt of an underlying crime was always a long shot. It was extraordinarily unlikely that he would find that Trump or high-ranking members of his presidential campaign “colluded”—or, to use the better and more precise legal term, conspired—with the Russian government to fix the 2016 election.

The improbability of success on “collusion,” narrowly construed, had nothing to do with the inherent morality of Trump and his handlers. After all, Trump chose as his campaign chairman Paul Manafort, a man so sleazy that even before his recent convictions had been cast out of American politics to practice his black arts on behalf of thugs and tyrants in the developing world and aspiring autocrats on the fringes of the former Soviet empire. Apart from thoroughly corrupt newcomers like Manafort and lightweight wannabe grifters like Rick Gates, Trump’s campaign was a family affair. Which meant that a chip off the old block like Donald Jr. was empowered to gleefully accept meetings with obviously dodgy Russian intermediaries offering obviously stolen dirt on candidate Hillary Clinton.

It was always vanishingly improbable that the Russians would connect themselves directly and provably to the campaign of a weak, imprudent huckster.

But however much the Trump ménage might have been willing to conspire with the Russians, it has always seemed improbable in the last degree that, during the campaign, the Russians ever got close enough to Trump that the interaction could be fairly categorized as a criminal conspiracy. A prosecutable conspiracy requires proof that two or more persons reached a tacit or express agreement to carry out a criminal objective.

The first problem with proving that Trump conspired in the legal sense with the Russians is identifying the criminal objective of the conspiracy. The second and equally daunting obstacle is proving an agreement to commit the object crime.

What we know of Russian activities in 2016 establishes that they did two basic things to help Trump and hurt Clinton—they certainly conducted a social media disinformation campaign that favored Trump and they almost certainly hacked Clinton campaign emails and fed them to the media through WikiLeaks.

As to the first, one might construe the millions of rubles expended on the Russian social media effort as an illegal foreign campaign contribution, but I am aware of no evidence suggesting that the Trump campaign had any more advance knowledge of the Russian efforts on this score than anyone else. Indeed, there is no reason to think the Russians would have said anything to Trump’s people about their work in this realm. They didn’t need Trump’s help to do what they were doing, and telling Trump—that famously indiscreet man—would have risked disclosure that would have nullified the whole point of the exercise.

As for the Clinton email leak, the original hack was illegal, but it is altogether unclear whether anything that happened thereafter was criminal. Legal experts have poured out barrels of internet ink arguing that for a foreign government or entity to give, and an American candidate to accept, negative information about an electoral opponent is a campaign finance violation. I’ve always found this contention improbable, both as a matter of law and as a matter of simple common sense.

Suppose, as was surely the case, that the British favored Hillary Clinton in the last election, and that, as was apparently not the case, they had evidence Donald Trump had long been a Russian intelligence asset. Can anyone seriously contend that it would be a crime under American law for the Clinton campaign to ask the British about their knowledge of Trump’s allegiances or indeed for the British to respond to the query? Even if one accepts the somewhat strained argument that information is a thing of value regulated by campaign finance law, no plausible reading of the First Amendment would permit criminalization of the disclosure of information so vital to the operation of the democratic process.

In any case, I strongly suspect that when the details of Mueller’s investigation finally emerge, they will reveal no evidence of prior communication between Trump’s people and the Russians about the Clinton email hack or the feeding of the material to WikiLeaks. An expression of interest in the emails by Donald Jr. at the Trump Tower meeting, yes. Loud public encouragement of the release from Trump, yes. Some advance word given to Roger Stone by Julian Assange (not the Russians) of the impending release of the material by WikiLeaks, perhaps. But no Trump-Russian cooperation in either obtaining or disseminating the material.

All of which makes perfect sense. The Russians perennially want to undermine their great geopolitical rival, the United States. They disliked Hillary Clinton for her past posture on Russian matters and perceived her as the more obviously competent—and thus undesirable—candidate in the 2016 election. Therefore, they were happy to attack her to weaken her support among the American public and to cause general disruption of American civic life. But—and this is a huge but—while it is now sometimes hard to remember, before Nov. 8, 2016, no sensible person—not the Russians and probably not even Trump himself—thought the American public would freely choose to elect such a transparently unqualified con man.

It was therefore always vanishingly improbable that the Russians would connect themselves directly and provably to the campaign of a weak, imprudent huckster, thus exposing Russia to the wrath of what the Russians surely assumed to be the incoming Clinton administration. Without such connections, there can have been no criminal conspiracy.

The situation with respect to obstruction of justice is different. It appears from Attorney General William Barr’s letter that Mueller did find evidence from which one might conclude that Trump obstructed justice, but elected not to opine on whether that crime was committed. We don’t yet know whether he did so because the evidence on both sides of the question was in rough equipoise, or because he concluded that the law is ambiguous, or because he decided that, since he could not under DOJ policy indict a president, he should not offer an affirmative opinion that the president committed a felony.

My best guess is that he intended that Congress and the public should weigh the evidence and arrive at their own conclusions. The Barr letter is a fairly transparent effort to frustrate that expectation by offering a pre-emptive and exonerating legal judgment carrying the imprimatur of the attorney general. It is also a peculiar animal because it effectively concedes that Trump did obstruct the Mueller investigation, in fact, but nonetheless concludes that Trump did not commit the crime of obstruction, primarily because Mueller did not find that Trump “was involved in an underlying crime related to Russian election interference.”

For what it’s worth, I think, Barr is wrong on the law. His heavy reliance on the absence of proof that Trump himself committed a crime connected with Russia is certainly misplaced. One can undoubtedly obstruct justice by interfering with an investigation of the crimes of someone else. Moreover, the law is clear that one can obstruct an investigation that ultimately does not yield proof of criminal wrongdoing by anyone. Barr’s contrary conclusion is only explainable as intellectually dishonest special pleading, or as the product of an intellectually honest, but constitutionally suspect, embrace of the so-called unitary executive view of the presidency, pursuant to which the president as the personal embodiment of the executive branch cannot obstruct justice by stopping investigation of anyone else.

But none of the foregoing is at all surprising. The chances of a smoking gun tying Trump to a provable electoral conspiracy with the Russians were always tiny. And any obstruction case was almost certainly going to turn on debatable views of presidential power and the importance of finding an underlying crime. This does not mean that the Mueller report itself, once revealed, will be of no consequence. One suspects it will reveal a wealth of discreditable detail about Trump and his clan. Still, whatever is in it will likely serve only to confirm his opponents’ disdain, even as his fans continue to hail it as exoneration.

For me, the most important question about the Mueller report is the issues it will leave unaddressed. For example, I have long thought that the Trump campaign’s contacts with Russia during the election were a mere secondary issue. The real question about Russia is why Trump has become a reliable, even obsequious, apologist for Vladimir Putin and has—so far as he has been able, against the resistance of Congress and the intelligence and defense establishments—regularly aligned himself with Russian interests. That requires explanation, and I strongly suspect Mueller did not read his charge as extending to an inquiry that would demand a deep historical analysis of Trump’s personal and business history running many years into the past. If the mystery of Trump’s open affinity for Putin is to be solved, congressional Democrats will have to solve it.

Which brings me to the three main lessons of the Mueller investigation.

The first is that Trump’s opponents have always invested far too much hope in Robert Mueller. He was asked to investigate one quite narrow segment of Trump’s affairs. He seems to have done so, vigorously, professionally, and dispassionately. But he was never going to be Trump’s Ken Starr, peering into every cranny of Trump’s life before and after the election for the silver bullet that would bring down a president. Mueller lacked the powers the old independent counsel statute gave Starr, and, happily I think, he lacks the zealotry that propelled Starr to the sordid fizzle of the Clinton impeachment. He has provided a salutary example of what the law, and the prosecutors who serve it, is supposed to do.

Bob Mueller’s legal investigation was never going to solve our national political crisis.

Second, the very narrowness of the Mueller inquiry should remind us that the problem with Donald Trump has never been one misdeed or misjudgment, or even one extended disgraceful episode. Nor is it the things we do not know about him (unless he really is compromised by Russia). The already-obvious challenge he presents to American democracy is his endless, staggering, mind-numbing array of completely public assaults on communal decency, competent governance, and bedrock constitutional norms. We don’t need Bob Mueller to tell us what the problem is. And almost nothing Mueller was ever likely to discover would have added very much to our understanding of that problem.

Bob Mueller’s legal investigation was never going to solve our national political crisis. And by not trying to solve it, by simply doing the job the Constitution and the laws asked him to do, he has paid the American system of government and his fellow citizens the great compliment of trusting us to solve it for ourselves. The truth is that both Democrats and Republicans have been hiding behind Bob Mueller for a long time. The shallow, vicious children of Trump’s media and congressional base have transformed him and the rest of the honorable men and women of federal law enforcement into an imaginary traitorous “deep state.” Among Democrats, “Wait for Mueller” has been the mantra of those either too cautious or too calculating to move boldly against a generational threat.

Now we are going to find out what 21st-century American democracy is made of. Will congressional Democrats have the fortitude to investigate those things that remain to be investigated—and do it both thoroughly and fairly? Will Republicans honor the example of their predecessors during Watergate and cooperate in seeking the truth? While waiting for its investigations to conclude, will Congress as a body defend its prerogatives and the constitutional balance against a president who plainly respects neither? And will it have the courage, once all investigations are complete, to act both on what they find and what is already staring them in the face? And even if our elected representatives fail us, will we employ the founders’ primary remedy against an overreaching or incompetent executive and vote to turn him out of the White House?

Bob Mueller is an old-fashioned man who has placed an old-fashioned faith in the regular processes of law and in our national commitment to intelligent self-government. I hope we are worthy of it.