– For nearly two years, President Donald Trump’s lawyers and defenders have argued that it was impossible for him to illegally obstruct the Russia investigation, no matter his intentions, because he has full authority over federal law enforcement as head of the executive branch.

But in his highly anticipated report, Robert Mueller rejected that sweeping view of executive power. Mueller’s team systematically dissected and repudiated such arguments, concluding over more than a dozen of the report’s 448 pages that obstruction laws did indeed limit how Trump could use his presidential powers.

“The conclusion that Congress may apply the obstruction laws to the president’s corrupt exercise of the powers of office accords with our constitutional system of checks and balances and the principle that no person is above the law,” they wrote.

Still, Mueller concluded that it would be inappropriate for now for prosecutors to make a decision — one way or the other — because analyzing the evidence “could potentially result in a judgment that the president committed crimes.” He reasoned that the Justice Department has for a half-century interpreted the Constitution as barring the indictment of a sitting president, so Trump could not get a trial and a chance to clear his name while he is running the country.

The special counsel’s rationale left the door open to the possibility that after Trump leaves office, prosecutors could re-examine the evidence Mueller gathered and charge the president. Attorney General William Barr tried to slam that door shut last month when he announced that in his view, the evidence did not support charging Trump regardless of any constitutional issues about charging sitting presidents.

Barr did not detail his thinking other than to note that Mueller had not found sufficient evidence to prove a criminal conspiracy between the Trump campaign and Russia. But months before the president nominated him as attorney general, Barr wrote a lengthy memo for the Trump administration laying out the very arguments that Mueller rejected.

Mueller’s report, which Barr made public Thursday with some redactions, laid out a wide-ranging effort by Trump to undermine the Russia investigation, painting a damning portrait of a president determined to wield his power to protect himself and his associates.

Many of the episodes Mueller detailed had been reported in the media. The president consistently sought to install a loyalist to oversee the investigation; tried to pressure Attorney General Jeff Sessions to retake control of the inquiry after he recused himself; and asked the FBI director to end the investigation into his first national security adviser.

Mueller also revealed new presidential attempts to thwart the inquiry. In mid-2017, Trump enlisted Corey Lewandowski, his former campaign manager, in another bid to impede the inquiry. Trump wanted Sessions to declare that the special counsel’s investigation was “very unfair” to the president and asked Lewandowski to convey the message. Lewandowski never directly spoke to the attorney general about the request, according to the report.

Mueller relied heavily on Trump’s White House counsel, Don McGahn, who told investigators about how Trump tried to have him fire Mueller in June 2017. The report said that McGahn stopped the effort, “deciding that he would resign rather than trigger what he regarded as a potential Saturday Night Massacre,” a reference to Richard Nixon’s firing in 1973 of the special prosecutor who was investigating him. That order, which caused the top two Justice Department officials to resign rather than carry it out, helped undermine political support for Nixon among Republicans.

The stark difference between Mueller’s rationale and the impression Barr had created last month was a central takeaway from Mueller’s report. Barr had not explained why Mueller declined to decide whether the evidence met the standard for charging Trump. Instead, he cited a fragment of Mueller’s rationale in what appears to be a misleading way.

In his letter, Barr wrote that Mueller had cited “difficult issues” of law and fact preventing him from deciding the obstruction question. Barr portrayed that murkiness — though he was not specific — as the barrier to Mueller’s ability to draw a conclusion “one way or the other.”

In fact, Mueller’s report contained a subtle but important difference from that impression. The special counsel cited those “difficult issues” as preventing him from exonerating the president of illegal obstruction — not as preventing him from accusing Trump of that crime.

“If we had confidence after a thorough investigation of the facts that the president clearly did not commit obstruction of justice, we would so state,” Mueller wrote. “Based on the facts and the applicable legal standards, however, we are unable to reach that judgment. The evidence we obtained about the president’s actions and intent presents difficult issues that prevent us from conclusively determining that no criminal conduct occurred.”

Instead, Mueller decided it would be unfair to analyze the evidence for now because it created the risk that he would conclude that Trump committed a crime with no possibility of a speedy trial to resolve whether that was true.

“An individual who believes he was wrongly accused can use that process to seek to clear his name,” Mueller wrote. “In contrast, a prosecutor’s judgment that crimes were committed, but that no charges will be brought, affords no such adversarial opportunity for public name-clearing before an impartial adjudicator.”

He added: “The concerns about the fairness of such a determination would be heightened in the case of a sitting President, where a federal prosecutor’s accusation of a crime, even in an internal report, could carry consequences that extend beyond the realm of criminal justice.”