Special counsel Robert Mueller. | AP Photo

Special counsel Robert Mueller has only just begun investigating whether President Donald Trump’s campaign colluded with Russia in last year’s election and whether Trump himself obstructed justice, but there are already fears that he’ll face pressure to reveal his conclusions before the 2018 midterms. While it’s unclear how long it will take Mueller to wrap up his investigation, veterans of past White House scandals say that with the midterms already being framed as a referendum on Trump’s presidency, both Republicans and Democrats can be expected to push Mueller to go public with whatever he has before voters go to the polls.

But Mueller will also be shadowed by the criticism heaped on former FBI Director James Comey over his public statements about the Hillary Clinton email probe in the days before the 2016 presidential election. “It’s going to be déjà vu all over again with respect to everyone being angry whatever he has to say,” said Douglas Kmiec, a former top Justice Department lawyer during the Ronald Reagan and George H.W. Bush administrations and U.S. ambassador to Malta under President Barack Obama. The special prosecutor doesn’t face a set deadline, and the regulations establishing Mueller’s office only say he must issue a final report to the Justice Department when he’s finished investigating spelling out why he believes criminal prosecutions are warranted or not – and nothing prevents him from pressing charges or speaking out before the entire report is complete. Most other major modern scandals involving the White House have dragged on for years, colliding with election campaigns. It took more than 1,200 days between the break-in at the offices of the psychiatrist for Pentagon Papers leaker Daniel Ellsberg, for example, and the final convictions of senior Nixon White House aides. During that time period, Nixon won a second term and he became the only president in U.S. history to resign from office.

Watergate represents one day First break-in to convictions: 1,216 days EXAMPLE 100 days May 19, 1973 | Day 624 Archibald Cox appointed as independent special prosecutor may 9, 1974 | Day 979 House impeachment hearings begin Aug. 8, 1974 | Day 1070 Nixon resigns Whitewater/Monica Lewinsky special counsel appointment to Senate acquitTal: 1,857 days Aug. 6, 1994 | Day 206 Kenneth Starr replaces Robert Fiske as special prosecutor Jan 16, 1998 | Day 1,465 Starr's probe expands to include alleged affair between Bill Clinton and White House intern Monica Lewinsky oct. 9, 1998 | Day 1,730 House votes to begin impeachment investigation dec. 19, 1998 | Day 1,802 House passes two articles of impeachment against Clinton Valerie Plame Wilson State of the Union to commuted conviction: 1,616 days oct. 28, 2005 | Day 1,004 DEC. 30, 2003 | Day 336 I. Lewis “Scooter” Libby, chief of staff to Vice President Dick Cheney, is indicted on obstruction of justice, false statements and perjury charges in leak case Attorney General John Ashcroft recuses himself from leak investigation. Deputy Attorney General James Comey announces new special counsel, U.S. Attorney Patrick Fitzgerald Mar. 6, 2007| Day 1498 Jury finds Libby guilty on four of five counts Russia Investigation DNC hack to present: 727 days July 25, 2016| Day 390 jan. 13, 2017 | Day 562 JULY ‘15 The FBI confirms it has opened an investigation into the hacking of the DNC computer network The Senate Select Committee on Intelligence announces that it will investigate “Russian intelligence activities” during the 2016 U.S. election 1 2 MAR. 2, 2017 | Day 610 Mar. 20, 2017 | Day 629 1 Attorney General Jeff Sessions recuses himself from any investigation into Russia and possible collusion with the Trump campaign FBI Director James Comey confirms an investigation into Russian interference in the election and possible collusion between Russia and the Trump campaign 2 3 4 4 3 May 17, 2017| Day 687 May 9, 2017| Day 679 Former FBI Director Robert Mueller appointed as special counsel Trump fires Comey Watergate represents one day First break-in to convictions: 1,216 days EXAMPLE 100 days May 19, 1,973 Day 624 Archibald Cox appointed as independent special prosecutor may 9, 1,974 Day 979 House impeachment hearings begin Aug. 8, 1,974 Day 1070 Nixon resigns Whitewater/Monica Lewinsky special counsel to Senate acquitTal: 1,857 days Aug. 6, 1994 Day 206 Kenneth Starr replaces Robert Fiske as special prosecutor oct. 9, 1998 Day 1,730 Jan 16, 1998 Day 1,465 House votes to begin impeachment investigation Starr's probe expands to include alleged affair between Bill Clinton and White House intern Monica Lewinsky dec. 19, 1998 Day 1,802 House passes two articles of impeachment against Clinton Valerie Plame Identity Leak State of the Union to commuted conviction: 1616 days DEC. 30, 2003 Day 336 oct. 28, 2005 Day 1,004 Attorney General John Ashcroft recuses himself from leak investigation. Deputy Attorney General James Comey announces new special counsel, U.S. Attorney Patrick Fitzgerald I. Lewis “Scooter” Libby, chief of staff to Vice President Dick Cheney, is indicted on obstruction of justice, false statements and perjury charges in leak case Mar. 6, 2007 Day 1,498 Jury finds Libby guilty on four of five counts Trump-Russia Investigation DNC hack to present: 727 days JULY ’15 jan. 13, 2017 Day 562 The Senate Select Committee on Intelligence announces that it will investigate “Russian intelligence activities” during the 2016 U.S. election July 25, 2016 Day 390 The FBI confirms it has opened an investigation into the hacking of the DNC computer network 1 2 3 4 1 2 3 May 9, 2017 Day 679 MAR. 2, 2017 Day 610 MAR. 20, 2017 Day 629 Attorney General Jeff Sessions recuses himself from any investigation into Russia and possible collusion with the Trump campaign FBI Director James Comey confirms an investigation into Russian interference in the election and possible collusion between Russia and the Trump campaign Trump fires Comey 4 May 17, 2017 Day 687 Former FBI Director Robert Mueller appointed as special counsel represents one day EXAMPLE 100 days Watergate First break-in to convictions: 1,216 days 1 2 3 1 May 19, 1973 | Day 624 Archibald Cox appointed as independent special prosecutor 2 may 9, 1974 | Day 979 House impeachment hearings begin 3 Aug. 8, 1974 | Day 1,070 Nixon resigns Whitewater/Monica Lewinsky special counsel apointment to Senate acquiTtal: 1,857 days 1 2 4 3 1 Aug. 6, 1994 | Day 206 Kenneth Starr replaces Robert Fiske special prosecutor 2 Jan 16, 1998| Day 1,465 Starr's probe expands to include alleged affair between Bill Clinton and White House intern Monica Lewinsky 3 oct. 9, 1998| Day 1,730 House votes to begin impeachment investigation 4 dec. 19, 1998| Day 1,802 House passes two articles of impeachment against Clinton Valerie Plame Identity Leak State of the Union to commuted conviction: 1,616 days 1 2 3 1 Dec. 30, 2003 | Day 336 Attorney General John Ashcroft recuses himself from leak investigation. Deputy Attorney General James Comey announces new special counsel, U.S. Attorney Patrick Fitzgerald 2 oct. 28, 2005 | Day 1,004 I. Lewis “Scooter” Libby, chief of staff to President Dick Cheney, is indicted on obstruction of justice, false statements and perjury charges in leak case 3 Mar. 6, 2007 | Day 1,498 Jury finds Libby guilty on four of five counts Russia Investigation DNC hack to present: 727 days JULY ’15 1 3 4 2 5 1 July 25, 2016 | Day 390 The FBI confirms it has opened an investigation into the hacking of the DNC computer network 2 jan. 13, 2017 | Day 562 The Senate Select Committee on Intelligence announces that it will investigate “Russian intelligence activities” during the 2016 U.S. election 3 MAR. 2, 2017 | Day 610 Attorney General Jeff Sessions recuses himself from any investigation into Russia and possible collusion with the Trump campaign 4 MAR. 20, 2017 | Day 629 FBI Director James Comey confirms an investigation into Russian interference in the election and possible collusion between Russia and the Trump campaign 5 May 9, 2017| Day 679 Trump fires Comey 6 May 17, 2017| Day 687 Former FBI Director Robert Mueller appointed as special counsel Watergate represents one day EXAMPLE First break-in to convictions: 1,216 days 100 days May 19, 1973 | Day 624 Archibald Cox appointed as independent special prosecutor may 9, 1974 | Day 979 House impeachment hearings begin Aug. 8, 1974 | Day 1,070 Nixon resigns Whitewater/Monica Lewinsky special counsel appointment to Senate acquiTtal: 1,857 days Aug. 6, 1,994 | Day 206 Kenneth Starr replaces Robert Fiske as special prosecutor Jan 16, 1998 | Day 1,465 Starr's probe expands to include alleged affair between Bill Clinton and White House intern Monica Lewinsky oct. 9, 1998 | Day 1,730 House votes to begin impeachment investigation dec. 19, 1998 | Day 1,802 House passes two articles of impeachment against Clinton Valerie Plame Identity Leak State of the Union to commuted conviction: 1,616 days DEC. 30, 2003 | Day 336 oct. 28, 2005 | Day 1,004 I. Lewis “Scooter” Libby, chief of staff to Vice President Dick Cheney, is indicted on obstruction of justice, false statements and perjury charges in leak case Attorney General John Ashcroft recuses himself from leak investigation. Deputy Attorney General James Comey announces new special counsel, U.S. Attorney Patrick Fitzgerald Mar. 6, 2007| Day 1,498 Jury finds Libby guilty on four of five counts Russia Investigation DNC hack to present :727 days July 25, 2016| Day 390 jan. 13, 2017 | Day 562 JULY ‘15 The FBI confirms it has opened an investigation into the hacking of the DNC computer network The Senate Select Committee on Intelligence announces that it will investigate “Russian intelligence activities” during the 2016 U.S. election 2 1 MAR. 2, 2017 | Day 610 Mar. 20, 2017 | Day 629 1 Attorney General Jeff Sessions recuses himself from any investigation into Russia and possible collusion with the Trump campaign FBI Director James Comey confirms an investigation into Russian interference in the election and possible collusion between Russia and the Trump campaign 2 3 4 4 3 May 17, 2017| Day 687 May 9, 2017| Day 679 Former FBI Director Robert Mueller appointed as special counsel Trump fires Comey Note: The exact date of the July, 2015 DNC attack has not been released.

President Bill Clinton was under investigation for more than 1,850 days over two terms as special prosecutors examined everything from his Whitewater land dealings while serving as Arkansas attorney general to his sexual affair with White House intern Monica Lewinsky. The Democrat was impeached by the House but the Senate acquitted him in early 1999 after a five-week trial.

Monica Lewinsky | Getty Images

A former senior Obama-era Justice Department official said the complexity of the case in front of Mueller could take considerable time because of international financial and intelligence information that won’t be easy to track down. But the source, who has worked with Mueller, said the former FBI director is well known for pushing staff to work overtime. “If he has one flaw or virtue it’s impatience. He moves people very hard and moves them very quickly,” the former DOJ official said. “The team will be sleep-deprived and sweating bullets as he drives them to wrap it up.” Any public disclosures on the Russia probe will be prime fodder for both Democrats and Republicans heading into the midterms. “It’s going to be hanging over every single congressional candidate,” said Bradley Moss, a Washington-based national security attorney. “Do you believe the president obstructed justice? Do you believe the president should be impeached?” Mueller so far has tried to operate out of the media spotlight as he learns the intricacies of what the FBI and Congress have already done on the Russia case, prepares his budget and hires a team of experienced investigators who have pursued such high-profile targets as Al Qaeda, Enron executives, the Mafia and Watergate. His spokesman, Peter Carr, declined comment for this story. At least five congressional committees have also launched investigations into different aspects of Russia’s election meddling – and Republicans running the probes say they’re in no rush to wrap them up. “If I talk to one witness and they give me someone else’s name, I’ve got to go find that witness and talk to them,” said Rep. Mike Conaway, the Texas Republican leading the House Intelligence Committee’s probe. “You’ve got to run the daisy chain of witnesses out.”

The congressional investigators and Mueller are all dealing with some complicated legal issues, exploring everything from the financial connections between Russia and Trump and his associates and questions about favorable policy treatment that the Republican president may have given to the United States’ longtime Cold War adversary. Investigators are looking into Russian influence on viral “fake news” and its spread on social media, as well as how Russian hackers got into Clinton campaign chairman John Podesta’s Gmail account. Trump’s move to fire Comey in early May – and Comey’s subsequent public testimony that the president had asked him to “let this go” regarding the Russia probe’s examination of former White House national security adviser Michael Flynn – is also within Mueller’s jurisdiction to investigate. Mueller, a former George W. Bush-era FBI director, has been on the job as the Russia special prosecutor for less than six weeks himself. But he’s already come under sharp criticism from Trump and his surrogates, who have been blasting away at his integrity and even floating the prospect he could be fired before he’s even got his probe off the ground. “We’ll have to see,” Trump told Fox News in an interview last Thursday where he also called it “very bothersome” that Mueller and Comey are “good friends” – a relationship that people close to the two men say is not accurate. “Jim and Bob are friends in the sense that co-workers are friends,” said Comey’s attorney, David Kelley. “They don’t really have a personal relationship. Jim has never been to Bob’s house and Bob has never been to Jim’s house.” Samuel Buell, a former federal prosecutor, said that it’s not too soon for Mueller to consider the heated political environment his team is working in over the coming year. “I think it would be impossible for any smart lawyer in Mueller’s position not to be thinking about timing with respect to the political process,” Buell said. “You can’t let it affect you in getting the investigative job done right, but to the extent there ends up being any discretion to exercise on the timing to things, you bet they will consider whether election season is underway.”

Austin Wright and Kyle Cheney contributed to this report.