Donald Trump has made sure that nobody who even remotely follows his actions has been able to forget the scandal of Hillary Clinton using a private server to store emails.

The president has repeatedly abused the former secretary of state since facing Clinton during the 2016 election campaign, with Trump supporters still chanting “lock her up” at rallies held by Trump close to three years into his presidency.

Investigations into Clinton’s use of email took place at various points, with tens of thousands of messages being handed over to authorities. The most famous was the FBI, then led by James Comey, interviewing her and then saying in July 2016 that there was no evidence that would lead to criminal charges being pursued. However, Comey did rebuke Clinton and her team for mishandling her emails – with some chains of messages containing top secret information.

According to the national archives, employees of government agencies should now generally only use personal email accounts in “emergency situations” and all emails should be stored according to record keeping guidelines.

Clinton’s case was then reopened at the end of October 2016, just over a week before the presidential election, with Comey saying further emails that could pertain to the investigation were found. The case was closed by 6 November, with Comey telling congress that after reviewing those emails, their view of the case had not changed after all.

The Democrat challengers to Trump in 2020 Show all 25 1 /25 The Democrat challengers to Trump in 2020 The Democrat challengers to Trump in 2020 Bernie Sanders The Vermont senator has launched a second bid for president after losing out to Hilary Clinton in the 2016 Democratic primaries. He is running on a similar platform of democratic socialist reform Getty The Democrat challengers to Trump in 2020 Joe Biden The former vice president recently faced scrutiny for inappropriate touching of women, but was thought to deal with the criticism well and has since maintained a front runner status in national polling EPA The Democrat challengers to Trump in 2020 Elizabeth Warren The Massachusetts senator is a progressive Democrat, and a major supporter of regulating Wall Street Reuters The Democrat challengers to Trump in 2020 Amy Klobuchar Klobuchar is a Minnesota senator who earned praise for her contribution to the Brett Kavanaugh hearings Getty The Democrat challengers to Trump in 2020 Michael Bloomberg Michael Bloomberg, a late addition to the 2020 race, announced his candidacy after months of speculation in November. He has launched a massive ad-buying campaign and issued an apology for the controversial "stop and frisk" programme that adversely impacted minority communities in New York City when he was mayor Getty Images The Democrat challengers to Trump in 2020 Tulsi Gabbard The Hawaii congresswoman announced her candidacy in January, but has faced tough questions on her past comments on LGBT+ rights and her stance on Syrian President Bashar al-Assad Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Pete Buttigieg The centrist Indiana mayor and war veteran would be the first openly LGBT+ president in American history Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Deval Patrick The former Massachusetts governor launched a late 2020 candidacy and received very little reception. With just a few short months until the first voters flock to the polls, the former governor is running as a centrist and believes he can unite the party's various voting blocs AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Beto O'Rourke The former Texas congressman formally launched his bid for the presidency in March. He ran on a progressive platform, stating that the US is driven by "gross differences in opportunity and outcome" AP The Democrat challengers to Trump in 2020 DROPPED OUT: Kamala Harris The former California attorney general was introduced to the national stage during Jeff Sessions’ testimony. She has endorsed Medicare-for-all and proposed a major tax-credit for the middle class AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Bill De Blasio The New York mayor announced his bid on 16 May 2019. He emerged in 2013 as a leading voice in the left wing of his party but struggled to build a national profile and has suffered a number of political setbacks in his time as mayor AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Steve Bullock The Montana governor announced his bid on 14 May. He stated "We need to defeat Donald Trump in 2020 and defeat the corrupt system that lets campaign money drown out the people's voice, so we can finally make good on the promise of a fair shot for everyone." He also highlighted the fact that he won the governor's seat in a red [Republican] state Reuters The Democrat challengers to Trump in 2020 DROPPED OUT: Cory Booker The New Jersey Senator has focused on restoring kindness and civility in American politics throughout his campaign, though he has failed to secure the same level of support and fundraising as several other senators running for the White House in 2020 Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Wayne Messam Mayor of the city of Miramar in the Miami metropolitan area, Wayne Messam said he intended to run on a progressive platform against the "broken" federal government. He favours gun regulations and was a signatory to a letter from some 400 mayors condemning President Trump's withdrawal from the Paris Climate Accord Vice News The Democrat challengers to Trump in 2020 DROPPED OUT: Kirsten Gillibrand The New York Senator formally announced her presidential bid in January, saying that “healthcare should be a right, not a privilege” Getty The Democrat challengers to Trump in 2020 DROPPED OUT: John Delaney The Maryland congressman was the first to launch his bid for presidency, making the announcement in 2017 AP The Democrat challengers to Trump in 2020 DROPPED OUT: Andrew Yang The entrepreneur announced his presidential candidacy by pledging that he would introduce a universal basic income of $1,000 a month to every American over the age of 18 Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Julian Castro The former San Antonio mayor announced his candidacy in January and said that his running has a “special meaning” for the Latino community in the US Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Marianne Williamson The author and spiritual adviser has announced her intention to run for president. She had previously run for congress as an independent in 2014 but was unsuccessful Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Eric Swalwell One of the younger candidates, Swalwell has served on multiple committees in the House of Representatives. He intended to make gun control central to his campaign but dropped out after his team said it was clear there was no path to victory Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Seth Moulton A Massachusetts congressman, Moulton is a former US soldier who is best known for trying to stop Nancy Pelosi from becoming speaker of the house. He dropped out of the race after not polling well in key states Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Jay Inslee Inslee has been governor of Washington since 2013. His bid was centred around climate change AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: John Hickenlooper The former governor of Colorado aimed to sell himself as an effective leader who was open to compromise, but failed to make a splash on the national stage Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Tim Ryan Ohio representative Tim Ryan ran on a campaign that hinged on his working class roots, though his messaging did not appear to resonate with voters Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Tom Steyer Democratic presidential hopeful billionaire and philanthropist Tom Steyer is a longtime Democratic donor AFP/Getty

Trump has refused to let it go, even mentioning it during a Q&A with reporters while meeting Ukraine’s president, Volodymyr Zelensky. Asked whether he believes there are missing Clinton emails in Ukraine (there is no evidence for this), Trump said: “I think there could be.” He was speaking after a July phone call with Zelensky that is at the centre of the Democrat-led impeachment investigation against Trump, where the president asked Zelensky for a “favour” that included helping look into the Clinton email scandal.

That call was also part of a whistleblower complaint that Democrats believe is key to the issue of impeachment – and that complaint has given Trump his own server-related case. It is likely to give him as much trouble as Clinton had with another election year around the corner.

The complaint – which comprises allegations from officials relating to an exchange that they say posed a risk to US national security – accuses White House officials trying to “lock down” the transcript of the call. The complaint alleges that the conversation between Trump and Zelensky was removed from the computer system that typically houses such records and was loaded onto a separate electronic system that usually houses information of an “especially sensitive nature”.

According to the complaint, one White House official told the whistleblower that this was likely an abuse of the system as there was nothing “remotely sensitive” about the call. In the words of the whistleblower, such action “underscored to me that White House officials understood the gravity of what had transpired on the call”.

Volodymyr Zelensky looks worried as Trump mentions Ukraine relationship with Russia

Trump says he has done nothing wrong. The White House states that the memo showed the contents of the call and the whistleblower complaint proved “no improper conduct” by the president.

Trump has repeatedly derided what he calls Clinton’s “corruption” and use of that private email server, but now Democrats are focused on this Ukraine issue – including the alleged moving of the call transcript. They are unlikely to let it drop.