WASHINGTON — Special counsel Robert Mueller did not find that Donald Trump or his campaign schemed with Russian efforts to interfere in the 2016 presidential election, according to a summary released Sunday that the president immediately embraced as a “complete exoneration” even though Mueller reached no conclusion about whether the president obstructed justice.

After a nearly two-year investigation, Mueller’s findings seemed to dispel the cloud of conspiracy that has hung over the administration since its inception. But by delivering caveats alongside conclusions, the closing of the Mueller investigation opens the door to fiercer political fights over the president’s judgment and power.

The four-page summary issued Sunday by Attorney General William Barr declared: “The Special Counsel’s investigation did not find that the Trump campaign or anyone associated with it conspired or coordinated with Russia in its efforts to influence the 2016 U.S. presidential election.”

The letter notes that Mueller’s probe said no such conspiracy was found “despite multiple offers from Russia-affiliated individuals to assist the Trump campaign.”

Barr said he and Justice Department officials separately determined that there was insufficient evidence to make an obstruction accusation against the president – though Mueller was not definitive on that point.

Trump spoke to reporters at a Florida airport Sunday afternoon, declaring that the dark cloud of suspicion that had hung over his administration since its inception had finally lifted.

“After a long look, after a long investigation, after so many people have been so badly hurt, after not looking at the other side, where a lot of bad things happened, a lot of horrible things happened for our country, it was just announced there was no collusion with Russia,” the president said, declaring the findings “a complete and total exoneration.”

“It’s a shame that our country had to go through this; to be honest, it’s a shame that your president has had to go through this,” Trump said, urging that Democrats be investigated.

On the question of whether the president might have sought to obstruct the high-profile investigation, Mueller’s team did not offer a definitive answer.

Special counsel Robert Mueller, and his wife, Ann, leave St. John’s Episcopal Church, across from the White House, after attending a service Sunday in Washington. Mueller closed his long and contentious Russia investigation with no new charges, ending the probe that has cast a dark shadow over Donald Trump’s presidency. Associated Press/Cliff Owen

“The Special Counsel … did not draw a conclusion – one way or the other – as to whether the examined conduct constituted obstruction,” Barr’s letter to lawmakers states.

“The Special Counsel states that ‘while this report does not conclude that the President committed a crime, it also does not exonerate him,’ ” the letter says, signaling that Mueller’s team apparently struggled with the issue.

“For each of the relevant actions investigated, the report sets out evidence on both sides of the question and leaves unresolved what the Special Counsel views as ‘difficult issues’ of law and fact concerning whether the President’s actions and intent could be viewed as obstruction,” the letter says.

Mueller’s decision to forgo a conclusion as to whether the president tried to obstruct justice struck a discordant note with current and former law enforcement officials, who noted that it was one of the primary reasons for appointing a special counsel.

“I think courageous people have the courage to make decisions, and those who don’t punt decisions,” said George Terwilliger, a former deputy attorney general who worked in the George H.W. Bush administration with Mueller and Barr.

Since his appointment in May 2017 as special counsel, Mueller has wrestled with the question of whether the president attempted to obstruct justice once the FBI began investigating those close to him. Current and former White House officials who were questioned by Mueller’s investigators were repeatedly asked about how the president spoke of the investigation behind closed doors, and whether he sought to replace senior Justice Department officials to stymie the probe, according to people familiar with the interviews.

Mueller “ultimately determined not to make a traditional prosecutorial judgment” on the question of obstruction, Barr wrote, so the attorney general and Deputy Attorney General Rod Rosenstein decided.

Rosenstein and Barr “concluded that the evidence developed during the special counsel’s investigation is not sufficient to establish that the President committed an obstruction of justice offense. Our determination was made without regard to, and is not based on, the constitutional considerations that surround the indictment and criminal prosecution of a sitting president,” Barr wrote.

Barr further explained that decision by writing that “the report identifies no actions that, in our judgment, constitute obstructive conduct, had a nexus to a pending or contemplated proceeding, and were done with corrupt intent, each of which, under the Department’s principles of federal prosecution guiding charging decisions, would need to be proven beyond a reasonable doubt to establish an obstruction of justice offense.”

Barr’s letter does not make clear whether Mueller asked Barr and Rosenstein to make a final determination on the question of obstruction.

“Over the course of the investigation, the Special Counsel’s office engaged in discussions with certain Department officials regarding many of the legal and factual matters at issue in the Special Counsel’s obstruction investigation,” it says.

A spokesman for Mueller declined to comment.

The top two Democrats in Congress accused the attorney general of bias and questioned his judgment in deciding that Trump had not committed obstruction, alluding to opinion pieces and a private memo Barr wrote before he became attorney general that were critical of some elements of Mueller’s work.

Barr’s letter “raises as many questions as it answers,” said Senate Minority Leader Charles Schumer, D-N.Y., and House Speaker Nancy Pelosi, D-Calif.: “Given Mr. Barr’s public record of bias against the special counsel’s inquiry, he is not a neutral observer and is not in a position to make objective determinations about the report.”

Schumer and Pelosi repeated their demand for the full report to be made public, saying “the American people have a right to know.”

Trump’s lawyers seized on a portion of the letter that said Mueller recognized “the evidence does not establish that the President was involved in an underlying crime related to Russian election interference.” That is not necessary to charge the crime of obstruction, Barr noted, but he added that “the absence of such evidence bears upon the President’s intent with respect to obstruction.”

It was unclear whether the White House will get to review Mueller’s full report. Justice Department officials have been silent on that question, though Barr’s letter strongly suggests that he intends to release a redacted version.

Barr said the Mueller report appears to contain grand jury material that is barred by law from being released, and that he will work with Mueller to identify which portions those may be, as well as any portions whose public release might compromise ongoing investigations.

The attorney general said his “goal and intent is to release as much of the Special Counsel’s report as I can consistent with applicable law, regulations, and Department policies.”

Brian Rabbitt, the attorney general’s chief of staff, called White House lawyer Emmet Flood and gave him a readout of the letter at 3 p.m., a senior Justice Department official said.

A Justice Department spokeswoman also called her White House counterpart to notify her of what was soon to happen.

“That is the extent of the conversation between us and the White House on the report thus far,” the official said.

Mueller’s central mission had been to determine if Russian efforts to interfere in the 2016 election were aided or assisted in any way by Americans, including people close to Trump.

In all, Russian citizens interacted with at least 14 Trump associates during the campaign and presidential transition, according to public records and interviews.

Of particular concern was the interaction between a London-based professor and a low-level Trump foreign policy adviser, George Papadopoulos. According to court filings, the professor told Papadopoulos in April 2016 that the Russians held damaging information about Trump’s opponent, Hillary Clinton, in the form of thousands of emails.

Mueller also dug into a June 2016 meeting at Trump Tower in New York. Trump’s son Donald Trump Jr. and Trump’s son-in-law Jared Kushner met with a Russian lawyer after being told she had incriminating information on Clinton that was being offered as part of the Russian government’s support for the GOP candidate, according to emails exchanged in advance of the meeting.

The lawyer has said she was not working on behalf of the Russian government. Trump Jr. and Kushner have said she did not provide any information about Clinton at the meeting.

Seeking to answer the collusion question, Mueller has also scrutinized the anti-secrecy group WikiLeaks, which released batches of Democrats’ emails that U.S. investigators say were stolen by Russian intelligence officers.

The special counsel’s work led to criminal charges against 34 people, including six former Trump associates and advisers.

On Saturday, officials said that one of those cases – that of Trump’s former deputy campaign chairman Rick Gates – will be transferred from the special counsel’s office to federal prosecutors in Washington. Gates pleaded guilty last year to conspiracy and lying to the FBI, and he continues to cooperate with prosecutors while awaiting sentencing.

A senior Justice Department official said the special counsel has not recommended any further indictments – a revelation that buoyed Trump’s supporters, even as additional Trump-related investigations continue in other parts of the Justice Department, in Congress and in New York state.

Rep. Jerrold Nadler, D-N.Y., the chairman of the House Judiciary Committee, said in a series of tweets that he wanted Barr to quickly testify before Congress to explain what the lawmaker called “very concerning discrepancies and final decision-making at the Justice Department following the Special Counsel report.”

Nadler said Mueller “clearly and explicitly is not exonerating the President, and we must hear from … Barr about his decision-making and see all the underlying evidence for the American people to know all the facts.”

Republicans cheered the findings.

Sen. Lindsey Graham, R-S.C., called the findings a “good day for the rule of law. Great day for President Trump and his team. No collusion and no obstruction. The cloud hanging over President Trump has been removed by this report. Bad day for those hoping the Mueller investigation would take President Trump down.”

Rep. Douglas Collins, R-Ga., the senior Republican on the House Judiciary Committee, said the investigation was “long, thorough and conclusive: There was no collusion. There is no constitutional crisis.”

He called on Democrats in Congress to now dial back their “sprawling” inquiries into the same issues.