The Mueller report is coming. Here’s what to expect.

Special counsel Robert Mueller is reportedly close to wrapping up his investigation. Appointed in May 2017, Mr. Mueller has been looking into whether members of the Trump campaign conspired with Russian agents to interfere in the 2016 election, as well as whether President Donald Trump engaged in obstruction of justice by firing then-FBI Director James Comey, publicly denouncing the investigation, and dangling potential pardons.

No direct evidence of a Trump-Russia conspiracy has emerged to date, although it remains unclear what Mr. Mueller and his team may have uncovered.

Since Justice Department guidelines suggest that a sitting president may not be indicted, whatever conclusions Mr. Mueller reaches will likely be delivered in a written report to the newly-confirmed attorney general, William Barr. It will then be up to Mr. Barr to determine how next to proceed and how much of the report to share with Congress and the public.

If the report contains substantial evidence of wrongdoing, it could become the basis of an impeachment proceeding in the House of Representatives. 

Will the report be made public?

Mr. Barr said during his confirmation hearing that he would make as much of the report public as possible, “consistent with the regulations.” Under Justice Department regulations, prosecutors are prohibited from releasing evidence gathered in a grand jury investigation. Mr. Barr may also decide not to release parts of the report in order to protect sensitive national security information.

The Justice Department typically does not announce that it has decided against prosecuting someone – in other words, prosecutors don’t reveal evidence of wrongdoing and then explain why that evidence did not warrant the filing of charges.

An exception to that practice took place in July 2016, when Mr. Comey announced that charges would not be filed against Hillary Clinton over her use of a private email server while serving as secretary of state.

Trump opponents, many of them Democrats, are pushing for Mr. Trump’s case to be handled the way Mrs. Clinton’s was. They want Mr. Mueller to outline in full detail any evidence of wrongdoing by the president and his associates, regardless of whether prosecutors believe it would justify criminal charges or impeachment.

Ironically, some of the president’s strongest supporters – including his son, Don Jr. – are also calling for broad disclosure of everything related to the Mueller investigation, including which Trump associates were placed under surveillance and what evidence, if any, was used to justify that action under the Foreign Intelligence Surveillance Act.

The decision about what to make public rests first with the attorney general. If information is turned over to Congress, it will then be up to Congress to decide whether to pursue impeachment or additional investigation. Evidence in an impeachment proceeding would eventually become public.

What might the Mueller report say about collusion? 

The first priority of the Mueller team was to identify whether Russia and members of the Trump campaign conspired to interfere in the 2016 presidential election. Mr. Mueller has indicted 12 members of Russian military intelligence for their alleged involvement in the hacking and public release of embarrassing emails from the Democratic Party and Clinton campaign officials. The indictment mentions various Americans, but it does not identify any American – let alone a Trump associate – as a co-conspirator. Of course, there is nothing to prevent Mr. Mueller from issuing a superseding indictment to include newly identified members of a broader conspiracy, including Trump associates.

The big remaining question is whether Trump campaign officials – or Mr. Trump himself – helped the Russians in any way in their theft or with the public distribution of the emails. That would amount to a criminal conspiracy between agents of a hostile foreign power and a U.S. presidential candidate to undermine American democracy. 

The special counsel’s conspiracy investigation appears to have centered in particular on three individuals: former Trump campaign chairman Paul Manafort, former Trump lawyer and “fixer” Michael Cohen, and Republican political operative and Trump friend Roger Stone.

Each was targeted by Mr. Mueller’s office for early morning raids involving more than a dozen federal agents who seized massive volumes of paper and electronic records. 

Roger Stone 

Investigators want to know whether Mr. Stone helped coordinate the release of the stolen emails to maximize their political damage to the Clinton campaign. To date, prosecutors have presented no evidence of such coordination. Instead, Mr. Stone was indicted on charges that he obstructed a congressional investigation by making false statements to the House Intelligence Committee and by trying to convince another witness to refuse to testify.

It is well known that Mr. Stone was trying during the 2016 election season to discover as much information as he could about the hacked emails. But the extent of his contacts with WikiLeaks and the Russians is unknown – at least so far.

It is not illegal to reach out to Russian agents or WikiLeaks to try to discover damaging information about a political opponent. But it is illegal to lie to Congress about any documents or text messages that might expose those efforts. 

Paul Manafort  

In many ways, Mr. Manafort was the most obvious suspect for alleged Russian collusion, having worked for years as a consultant to pro-Russian political figures in Ukraine. A key member of his staff had links with Russian intelligence, according to a U.S. intelligence assessment. At one point during the 2016 campaign, Mr. Manafort is reported to have shared confidential polling data with this associate.

The full significance of that sharing, if accurate, is not yet known. If, for example, the data was turned over to Russian agents and was used to target particular groups in the U.S. or for other strategic political purposes to damage the Clinton campaign, that action would likely constitute a criminal conspiracy to interfere in the 2016 election.

Mr. Manafort also had a potential motive for helping the Russians, in that he owed a Russian oligarch, Oleg Deripaska, a substantial amount of money.

The problem with these theories is that they are only theories. Mr. Manafort has been convicted of tax evasion and bank fraud, and pled guilty to witness tampering and failing to register in the U.S. as a lobbyist for Ukraine. But he has not been charged with engaging in a conspiracy to fix an American election – at least not yet.

Mr. Manafort is set to be sentenced Thursday and next week, in two different jurisdictions. The 69-year-old political consultant could spend the rest of his life in prison. Under these circumstances, he has a strong incentive to cooperate with prosecutors. But some believe Mr. Trump is considering issuing a presidential pardon, which might encourage Mr. Manafort to be less than completely forthright with investigators. 

Michael Cohen 

In his controversial and still largely unconfirmed “dossier,” former British intelligence officer Christopher Steele wrote that Russian sources told him that Trump’s lawyer, Michael Cohen, played a key role in a covert Trump campaign-Kremlin conspiracy to undercut the Clinton campaign.

One entry, dated Oct. 19, 2016, said: “According to [a] Kremlin insider, Cohen now was heavily engaged in a cover up and damage limitation operation in the attempt to prevent the full details of Trump’s relationship with Russia being exposed.”

A second dossier entry, dated Oct. 20, 2016, said that Mr. Cohen met in August 2016 with Kremlin officials in Prague, in the Czech Republic.

A third, dated Dec. 13, 2016, said that Mr. Cohen went to Prague with three associates during the last week of August or the first week of September. “According to [Steele’s source], the agenda comprised questions on how deniable cash payments were to be made to hackers who had worked in Europe under Kremlin direction against the Clinton campaign and various contingencies for covering up these operations and Moscow’s secret liaison with the Trump team more generally.”

The dossier said the hacker-operatives were paid “by both Trump’s team and the Kremlin.”

Asked in a public hearing on Feb. 27 before the House Oversight Committee whether he had traveled to Prague in 2016 for any secret cover-up meetings with the Russians, Mr. Cohen denied it. He added that he did not meet with any Russians anywhere in Europe in 2016.

“Questions have been raised about whether I know of direct evidence that Mr. Trump or his campaign colluded with Russia. I do not,” Mr. Cohen said in his House testimony.

He added: “But, I have my suspicions.”

Mr. Cohen did testify about hearing Don Jr. tell his father, “the meeting is all set” – a comment he believes referred to the June 2016 Trump Tower meeting between top members of the Trump campaign and a Russian lawyer, in which campaign officials were told they would receive “dirt” on Mrs. Clinton. According to Mr. Cohen, Mr. Trump replied: “OK good.... Let me know.”

No charges have been filed related to the Trump Tower meeting, but it has been a source of media focus because it could suggest a possible conspiracy to receive and publicize emails allegedly stolen by Russian agents.

One of the lingering mysteries of the campaign is why Mr. Trump seemed to go out of his way to paint Russian leader Vladimir Putin in a positive light.

Some Trump critics have suggested it was because the Kremlin held compromising and embarrassing material against Mr. Trump. Former acting FBI Director Andrew McCabe said that he and others suspected in the spring of 2017 that the newly elected president may even have been acting as a Russian agent.

But Mr. Cohen’s testimony points to a different explanation as to why Mr. Trump was reluctant to criticize Mr. Putin during the presidential campaign in 2016.

Mr. Cohen said Mr. Trump never expected to win the election, and instead viewed the campaign as an opportunity to highlight the Trump brand. And he may have been currying favor with Mr. Putin to try to win approval for a proposed Trump Tower project in Moscow.

“He never expected to win the primary. He never expected to win the general election,” Mr. Cohen told Congress. “The campaign – for him – was always a marketing opportunity.”

That might explain why Mr. Cohen continued negotiating a Moscow tower deal at least through June 2016. Mr. Cohen pled guilty to lying to Congress in 2017 when he claimed, falsely, that the Moscow project negotiations ended in January 2016.

Mr. Cohen said Mr. Trump kept the ongoing negotiations secret “because he stood to make hundreds of millions of dollars on the Moscow real estate project.”

If there is no evidence of a conspiracy to fix the election, was the collusion narrative a ‘hoax’? 

Devin Nunes, the ranking Republican on the House Intelligence Committee, says he believes members of the Clinton campaign worked with sympathetic Obama administration officials at the FBI, Justice Department, and CIA to use unproven allegations in the Steele dossier to open a counterintelligence investigation into members of the Trump campaign.

“This was the Democratic Campaign Committee working with the Clinton campaign that produced this dirt and fed it into the FBI to start this investigation in the first place.” Mr. Nunes said in a Fox News interview on Sunday. “No collusion, no collusion conspiracy, no obstruction.”

But not everyone on Capitol Hill has abandoned talk of a Trump-Russia conspiracy.

Adam Schiff, the Democratic chairman of the House Intelligence Committee said in a recent interview on CBS’s Face the Nation that he believes there is “direct evidence of collusion,” notwithstanding Mr. Cohen’s recent public testimony.

He says the evidence includes emails, through an intermediary, from Russians offering “dirt” on Mrs. Clinton. “They offer that dirt. There is an acceptance of that offer in writing from the president’s son, Don Jr., and there are overt acts in furtherance of that,” Mr. Schiff said. Those “overt acts” include the June 2016 meeting at Trump Tower and the various lies to cover up that meeting.

Mr. Manafort’s sharing campaign polling data with his associate in Ukraine is also strong circumstantial evidence of collusion, according to Mr. Schiff. And Mr. Cohen’s testimony about overhearing a phone conversation between Mr. Stone and Mr. Trump about WikiLeaks’ plans to release stolen emails is further evidence, he said.

Still, “while there is abundant evidence of collusion, the issue from a criminal point of view is whether there is proof beyond a reasonable doubt of a criminal conspiracy,” Mr. Schiff said. “And that is something that we will have to await Bob Mueller’s report and the underlying evidence to determine.”

If Mueller report finds no conspiracy, will that exonerate the president?

Not necessarily. Mr. Mueller and his team have also been investigating whether Mr. Trump engaged in obstruction of justice when he fired Mr. Comey in 2017. The special counsel has examined whether Mr. Trump exerted improper influence when he reportedly asked Mr. Comey if he might consider dropping an investigation into National Security Advisor Michael Flynn’s contacts with the Russian ambassador. And there are questions about whether Mr. Trump sought to obstruct the investigation when he publicly raised the possibility of presidential pardons at a time when Mr. Mueller was trying to exert pressure on individuals to cooperate with prosecutors.

What other investigations might the president face?  

Mr. Trump may celebrate the release of the Mueller report, particularly if it finds no collusion between his campaign and Russia. But the end of the two-year probe will have little, if any, effect on an array of other investigations, hearings, and lawsuits that will dog Mr. Trump and his associates at least through the 2020 presidential election.

Democrats in Congress are beginning to pivot away from a sharp focus on Russian collusion to embrace a broader range of allegations about Mr. Trump, his family, his associates, and his business. The new focus appears to be on alleged abuses of power.

This effort gained momentum with Mr. Cohen’s recent testimony. While Mr. Cohen expressed doubt about whether Mr. Trump conspired with the Russians to interfere in the 2016 election, he nonetheless suggested several other areas of potential wrongdoing by the president and his associates. Chief among them is whether Mr. Trump conspired with Mr. Cohen to violate federal campaign finance laws, a matter being investigated by prosecutors in the Southern District of New York.

Mr. Cohen pleaded guilty last year to making an illegal campaign contribution to Mr. Trump when he arranged for a $130,000 hush-money payment to former adult film actress Stormy Daniels to prevent her from going public with allegations that she and Mr. Trump had engaged in an extramarital affair. The payment took place in the final days of the 2016 presidential campaign.

In his testimony before Congress, Mr. Cohen said he was directed by Mr. Trump to make the payment, and that Mr. Trump promised to reimburse him. He presented a copy of a signed personal check that he said Mr. Trump gave him as partial repayment.

At issue is whether Mr. Trump’s involvement in the hush-money payments is a violation of campaign finance laws, and whether that violation would warrant impeachment.

If the payment was campaign-related, it should have been publicly disclosed under the campaign finance reporting system. But if it was primarily a private matter – in which Mr. Trump was attempting to prevent his family from learning of his alleged affair – and was paid for with Mr. Trump’s own money, there would be no requirement for disclosure.

Apart from criminal investigations, various Democrat-controlled committees in Congress are expected to begin aggressive oversight hearings dealing with controversial aspects of the Trump presidency.

Jerrold Nadler, the Democratic chairman of the House Judiciary Committee, has reached out to 81 Trump associates seeking documents and information that might shed light on a wide range of suspected questionable activities by the Trump Organization, the Trump campaign, and the Trump administration.

Representative Nadler is seeking documents or information revealing any financial transactions with the Russian government or any Russian individual; any gifts or emoluments from a foreign government; any information about the proposed Trump Tower Moscow project; any details about the June 2016 Trump Tower meeting; information on changes made to the Republican platform concerning U.S. support for the Ukrainian armed forces facing off against Russian troops; any attempt to share 2016 election or polling information with foreign individuals; any discussions involving U.S. sanctions against Russia; any contacts with WikiLeaks; and the content of private meetings between Mr. Trump and Mr. Putin in 2017 and 2018.

The House Oversight Committee also heard from Mr. Cohen that Mr. Trump inflated the value of his assets to boost his net worth on paper, but understated the value of his assets to help reduce his tax liability. A number of committee members questioned Mr. Cohen closely about which members of the Trump Organization might be able to address such issues. It appears a goal of many members of the committee will be to obtain a copy of Mr. Trump’s tax returns, which he has so far refused to release.