GEORGE W. BUSH, the former president, earned headlines with a recent speech that—while it did not name President Donald Trump—unmistakably rebuked his Republican successor for degrading America’s national discourse with divisiveness and even “casual cruelty”. Yet his weightiest words came moments later, when Mr Bush urged America to secure both its electoral infrastructure and democratic system against subversion by foreign powers. This time he named names. “According to our intelligence services, the Russian government has made a project of turning Americans against each other,” the 43rd president said. He added that foreign aggressions—including cyber-attacks, the spreading of disinformation via social media or financial influence—“should not be downplayed or tolerated”.

Almost a year after his victory, and despite numerous revelations of Russian-funded attempts to stoke racial, religious and ethnic conflicts during the 2016 election, downplaying the attacks remains Mr Trump’s default response. In discussions of Russian misconduct, the president sees a bid by Democrats, the “fake media” and other perceived enemies to undermine the legitimacy of his victory. As Senator Lindsey Graham of South Carolina, a Republican foreign-policy hawk, told NBC, the Trump administration has “a blind spot on Russia I still can’t figure out”.

Congress is running three separate Russia-related investigations, all of which are supposed to answer Mr Graham’s question. None looks likely to do get to the bottom of it. Small wonder, then, that those Americans anxious to know more about who attacked their political system last year, and what could be done to prevent a repeat, pin such hopes on a probe led by Robert Mueller, who was appointed special counsel in May 2017 with a broad remit to investigate whether Russians tried to swing the election, and whether anyone in America tried to help them.

Ardent believers in Mr Mueller, a craggy faced former FBI boss under Republican and Democratic presidents, hope for a day when the super-prosecutor sweeps aside the tangles of partisan claims and counter-claims and lays criminal charges against those guilty of aiding and abetting Russia. Such folk imagine a moment with the satisfying finality of a Hollywood G-man bursting into a mafia hideout. Mr Mueller, for his part, has not said when his work will be wrapped up, nor whether he will press any criminal charges.

That official silence has been filled with speculation about what he is up to, based on clues such as the prosecutors he has hired for his team, his empanelling of a grand jury and a raid that he had conducted on the home of Paul Manafort, a former Trump campaign chairman who spent lucrative years as a political consultant, including to pro-Russian candidates in Ukraine. The latest mini-leak cheered Republicans, when NBC News reported that a Democratic lobbying firm founded by Tony Podesta, the brother of Hillary Clinton’s campaign chief John Podesta, had been quizzed by Mr Mueller’s team about work for a Ukrainian client of Mr Manafort’s that was not at first declared under rules governing foreign lobbying.

People with long experience of how special counsels operate—including former federal prosecutors and government officials who have known Mr Mueller for years, who spoke to The Economist on condition of anonymity—warn that Americans may need to steel themselves for a more ambiguous, and unhappily political, ending to his work. To start with their simplest advice, it is a mistake to assume that leaks or purported leaks are a good way to map the investigation. Because official Washington is agog at the idea of members of Mr Trump’s inner circle or family facing prosecution, most leaks involve what one expert calls “Trump people stuff”. Mr Mueller’s most significant work could involve a counter-intelligence probe built around closely-held secret evidence of National Security Agency intercepts of Russians talking to Russians, they say.

Nor is it possible to deduce much from the fact that a grand jury has been formed to help Mr Mueller. One former prosecutor describes this as a “normal tool” of any serious investigation. Another person scoffs at reports that Mr Mueller has recruited a dream team of lawyers skilled in scaring suspects into turning on their colleagues. Persuading witnesses to co-operate, at times with threats of prison time, is the work of any decent prosecutor, he notes.

There has been plenty of speculation about Mr Trump’s firing of James Comey, the FBI boss he inherited from Barack Obama, and whether that dismissal might trigger obstruction-of-justice charges. Mr Comey has said since his firing that Mr Trump asked him if he could see his way to dropping a probe into Michael Flynn, a former three-star general sacked as national security adviser for keeping quiet about contacts with Russians. But obstruction of justice is hard to prosecute unless clearly nefarious motives can be proven, says one experienced federal prosecutor. If Mr Trump were able to argue that he simply wanted to let Mr Flynn go quietly into retirement, any case might crumble.

One rule to follow is that “good prosecutors don’t do bullshit cases”. That means avoiding weak cases, but also small ones against minor figures that do not provide accountability when great wrongs are alleged. Mr Mueller is frequently described as a principled “Boy Scout”, whose mission is not to collect political scalps but to investigate something exceedingly serious, namely that Russia tried to sway an election. He has sweeping powers. It is quite plausible that he already has the tax returns that Mr Trump refused to make public. Those may or may not show that Mr Trump’s business empire was at some point propped up by funds or complex financial structures with links to Russian nationals—though the president denies receiving Russian loans. But even the most dramatic revelations might not involve criminality, warns one person. One plausible scenario is that Mr Mueller finds that Russia’s government did indeed attack America, and that Mr Trump is more beholden to Russian interests than he admits, but does not find evidence of collusion that justifies prosecutions.

If Democrats take control of one or more chambers of Congress in the mid-term elections of 2018, then they could attempt to impeach Mr Trump, triggering yet another partisan fight. Alternatively, Mr Trump could review Mr Mueller’s report, declare it “fake news” and recommend to the Department of Justice that it should not be made public. These scenarios are just guesses, our sources concede. But one thing above all seems probable: for all that many Americans long for clarity, this saga will have a political ending.