The special counsel Robert Mueller’s language, as quoted by Attorney General William Barr, is vague enough to bear numerous interpretations. Photograph by David Butow / Redux

Why didn’t the special counsel, Robert Mueller, reach a judgment on whether Donald Trump has obstructed justice? Forty-eight hours after William Barr sent his four-page letter to Congress, in which he revealed that the special counsel had punted on one of the two central issues of his investigation, we still don’t have a clue. Indeed, the mystery has deepened.

On Monday, the Wall Street Journal reported that Mueller told Barr three weeks ago that he didn’t intend to come to any conclusions on whether Trump’s actions in office, which included asking the former F.B.I. director James Comey to “go easy” on his former national-security adviser Michael Flynn and eventually firing Comey outright, amounted to criminal obstruction. The Journal’s story said that Mueller gave this information to Barr and the Deputy Attorney General, Rod Rosenstein, in a meeting on March 5th. Citing “a person familiar with the matter,” the news story said that Barr and Rosenstein were “surprised” by Mueller’s decision, and that Mueller “made that decision on his own.” You bet that Barr and Rosenstein were surprised. It’s been pretty clear all along that Trump’s lawyers were more worried about obstruction of justice than collusion, and on Tuesday a report from NBC News confirmed this. According to the NBC report, the President’s lawyers “never seriously worried their client would be accused of a Russia conspiracy.” They believed that “the real threat was obstruction of justice.”

In a post published shortly after Barr’s letter was released, I wrote that Mueller’s failure to reach a conclusion on obstruction “looks like a cop-out.” That was strong language, perhaps, but Mueller’s inaction also startled some veterans of the Justice Department. “I was shocked and remain somewhat bewildered as to why the special counsel did not conduct the customary balancing tests set out by the principles of federal prosecution, the guidebook for all prosecutors, by assessing whether there was sufficient admissible evidence to charge the President with obstruction,” David Laufman, a Washington lawyer who has held a number of senior jobs at Justice, including heading up its national-security division’s Counterintelligence and Export Control Section, told MSNBC’s Rachel Maddow on Monday night. “We just don’t have any visibility as to what his reasons were.”

Maddow asked Laufman if Mueller might have believed, for whatever reason, that he didn’t have the option of issuing a judgment. “It is a possibility,” Laufman replied. “But . . . then why go through the exhaustive effort of conducting one of the most probing criminal investigations in the history of the Department of Justice, and leave it in an unresolved state—in essence, putting at risk the work he did by committing it to the discretion of the two most senior political appointees in the Department of Justice, who, not unexpectedly, filled that void by substituting their judgment for the judgment we expected the special counsel to exercise?”

Why, indeed? Barr’s letter provided a bit of insight into Mueller’s thinking, but not much. It said that the second half of Mueller’s report “addresses a number of actions by the President—most of which have been the subject of public reporting—that the Special Counsel investigated as potentially raising obstruction-of-justice concerns. After making ‘a thorough factual investigation,’ the Special Counsel considered whether to evaluate the conduct under Department standards governing prosecution and declination decisions but ultimately determined not to make a traditional prosecutorial judgment.”

This language is vague enough to bear numerous interpretations. We’ll have to wait for Mueller’s actual report to see whether he expanded upon why he “ultimately determined” not to render a judgment, and whether he consulted with anyone outside of his investigation about this. In the meantime, some legal experts are defending the decision to punt.

Marty Lederman, a law professor at Georgetown University who worked at the Justice Department under the Obama Administration, told me that the special counsel may well have ruled out coming to a conclusion because any criminal case would revolve around the tricky issue of intent. “It is highly unlikely a special counsel or an attorney general is going to start the process of asking a jury to parse a President’s motives,” Lederman said. “Given that is the case, there is no real value in opining on whether the extraordinary actions of the President in this case amounted to obstruction of justice. What’s important is to lay out the facts clearly.” Lederman added that he holds this opinion despite the fact that he also believes that some of Trump’s actions, such as trying to fire Jeff Sessions and other efforts to undermine the special counsel’s investigation, were “extraordinarily deviant” and “would arguably satisfy the legal grounds for impeachment.”

Unless the full version of the Mueller report contains something very shocking that hasn’t previously been disclosed, there almost certainly isn’t going to be an impeachment. Nancy Pelosi, the Democratic Speaker of the House, signalled her opposition a couple of weeks ago, and Mueller’s failure to “establish that members of the Trump Campaign conspired or coordinated with the Russian government in its election interference activities” has shifted the political topography. On Monday, a number of Democratic representatives who previously supported starting impeachment proceedings indicated that they have changed their minds.

But, before resolving the question of impeachment, we need to learn much about what Mueller’s team found, what it didn’t find, and why he determined not to decide whether the President obstructed justice. To be sure, Mueller may have had some defensible arguments for his inaction. But it’s hard to sustain the claim that a judgment from him wouldn’t have had any practical value.

It would have had an enormous impact. If Mueller had said the evidence wasn’t sufficient to establish that Trump obstructed justice, the White House’s victory would have been complete. If Mueller had said the balance of evidence indicated that Trump did obstruct justice, impeachment would have been back on the table, although still unlikely to succeed, given the President’s grip on the G.O.P. In any case, though, a statement from an independent prosecutor that there were sufficient grounds for prosecution would have had great political and symbolic importance. It would have shown that, even if a President can’t be frog-marched into court while he is in office, he is still not above the legal process.

Rather than reaching a decision, the special counsel wrote, “While this report does not conclude that the President committed a crime, it also does not exonerate him.” That left the entire thing up in the air. I’m sticking with my original opinion: it looks like a cop-out.