Six months on, as it becomes clear that Mueller's investigation represents an existential threat to Trump's administration, the President's supporters have changed their tune. To Infowars host Alex Jones, Mueller is "the literal swamp king creature come to kill America". President Donald Trump speaks during a cabinet meeting at the White House, on Wednesday. Credit:AP Thanks to Mueller's investigation, we learned this week that for six months in 2016, including during the Republican Convention, Trump's campaign was run by an alleged foreign agent. Paul Manafort was no longer working for a Russian puppet regime in Ukraine but was still, according to charges filed on Monday, laundering "tens of millions of dollars" of the proceeds. His arrest was expected. George Papadopoulos' guilty plea, unsealed the same day, was not.

In this, we learned that a member of Trump's team was offered hacked emails damaging to Hillary Clinton by people he "understood to have substantial connections to Russian government officials", that he was encouraged by his superiors to pursue the lead, tried to set up an "off the record" meeting between Trump and Vladimir Putin, and then lied to the FBI about it. Robert Mueller in 2013. Credit:AP Mueller's reputation as a relentless prosecutor is deserved. Trump loyalists have cause to be concerned. "They're worried about him, not just because of what he's on to, but because he's extremely good," says Samuel Buell, who prosecuted the Enron case and now teaches law at Duke University. Paul Manafort, a former campaign worker for Donald Trump. Credit:Bloomberg

"He also has a sterling independent reputation. If you're saying Mueller can't be fair, you're showing that it isn't really about fairness: you just don't want the guy doing the job." The President, in a call with a New York Times reporter, projected blithe confidence: "I'm not under investigation, as you know … It has nothing to do with us." Then Trump campaign aide Rick Gates at the Republican National Convention in 2016. Credit:AP His chief of staff, John Kelly, told Fox News: "I think the reaction of the administration is let the legal justice system work, everyone's innocent until – presumed innocent – and we'll see where it goes." This is at odds with the message being hammered home on Fox. This version of reality has it that Mueller is compromised by his relationship with sacked FBI director James Comey, that the Clinton campaign "colluded" by funding the infamous Steele dossier documenting Trump's Russian ties, and that the "real scandal" is a uranium deal with the Russian nuclear agency, supposedly approved by Clinton in return for bribes.

Sam Clovis with then Republican candidate Donald Trump in 2016. Credit:AP Jeanine Pirro, the host of Justice with Judge Jeanine, put it bluntly: "Special Counsel and former FBI director Robert Mueller must be fired immediately. His role as head of the FBI during the uranium deal and the Russian extortion case, his friendship with Jim Comey, demand his firing." Manafort and his associate Rick Gates have pleaded not guilty to all charges, and the defiant statement from Manafort's lawyer, asserting that "the Russia collusion narrative is fake news", indicates Mueller may have a hard time turning the former campaign chairman against his old boss. Paul Manafort, left, leaves Federal District Court in Washington on Monday. Credit:AP "An indictment has a way of focusing the mind," says former assistant US attorney Randall Eliason, now a law professor at George Washington University.

"[Manafort] has been resistant, clearly, but now that he's faced with the reality of more than a decade in prison … his incentive to co-operate has got dramatically greater." Papadopoulos was arrested on July 27, and pleaded guilty to the relatively minor charge of making false statements on October 5. In a motion to keep the case sealed, Mueller's team described him as a "proactive cooperator" - language that suggests he has been secretly recording conversations with his former colleagues. "Normally when federal investigators work with a witness in that form, they want tape recordings," says Buell. The Washington Post has identified the unnamed supervisors in court documents as Manafort, Gates, campaign co-chair Sam Clovis and campaign manager Corey Lewandowski. Attorney-General Jeff Sessions is also implicated, as he attended the March 31 "national security" meeting at which Papadopolous pitched his Russian connections. Sessions now faces accusations of lying under oath at his confirmation hearing, where he denied any knowledge of contact between the Trump campaign and Russia.

"The mere fact that they were party to conversations does not suggest culpability," says Jacob Frenkel, a former federal prosecutor. "There is conduct here that may be perceived as sinister and unseemly, but … if the Russians had already developed a body of information about Hillary Clinton, and nobody in the Trump camp induced or enticed Russians to secure that information, then there may be no violation of law." Eliason disagrees, and says there are "a number of different options" prosecutors could pursue, including conspiracy to defraud the United States and conspiracy to violate the Computer Fraud and Abuse Act. The Manafort and Gates indictments and the Papadopoulos plea deal are merely the first cards Mueller is showing. Meanwhile Trump's defenders are jumping to the task. Fox host and Trump confidant Sean Hannity has been warning of a "deep state conspiracy" to undermine the President for months, and has hosted guests pushing the thoroughly debunked Uranium One story – the sale of a controlling stake in a Canadian mining company, approved by several regulatory bodies – more than 30 times. "This has been a HORRIBLE week for Mueller," Hannity tweeted. "THIS IS ALL A DISTRACTION."

In the Wall Street Journal, David Rivkin and Lee Casey called for Trump to issue "a blanket presidential pardon to anyone involved in supposed collusion with Russia", suggesting this would be analogous to Abraham Lincoln pardoning Confederate soldiers after the US Civil War. New York Post columnist Michael Goodwin argued that "special counsel Robert Mueller will never be able to untangle the tangled webs with any credibility and needs to step aside". (Fox, the Journal and the Post are all owned by Rupert Murdoch.) Republican congressman Devin Nunes has announced an investigation into the Uranium One deal, in partnership with Trey Gowdy, who led the Benghazi hearings that attempted to pin responsibility for the deaths of four Americans killed in a terrorist attack on Clinton. As chairman of the House Intelligence Committee, Nunes is also charged with investigating Russian interference in the presidential election, but is manifestly too partisan to do so credibly.

But could Trump fire Mueller, as his supporters crave? Republican senator Roy Blunt has said it would be "a big mistake", and fellow Republicans Charles Grassley, Orrin Hatch, Mike Lee and John McCain have all issued coded warnings. Trump is weak – his legislative agenda is stalled and his approval rating is historically low, at 33 per cent in the latest Gallup poll – but he continues to enjoy the support of his own party, at least in public. "When push comes to shove, what are Republicans in Congress going to do? That is the ultimate question here," says Buell. "We're getting mixed signals." Trump certainly has the constitutional right to pardon Manafort, should he so desire. In August he pardoned sheriff Joe Arpaio, who had been convicted of contempt of court for refusing to stop racially profiling Hispanic drivers. As well as a nod to his white nationalist base, this was a signal that Trump will look after his own, using all available powers. A pardon would only apply to federal crimes, and New York Attorney-General Eric Schneiderman also has Manafort in his sights. Anyone pardoned would lose their Fifth Amendment right to silence, should Mueller later call on them to testify. Plus, pardoning Manafort may cost Trump more political capital than he has to spend.

On October 20, 1973, as the Watergate scandal threatened to engulf his presidency, Richard Nixon fired special prosecutor Archibald Cox. Attorney-General Elliot Richardson and Deputy Attorney-General William Ruckelshaus resigned in response, and within 10 months Nixon himself had quit rather than face impeachment proceedings. Eliason says the "Saturday Night Massacre" should serve as a warning to Trump as he contemplates his next move. "Anything Trump does, whether it's pardoning people or firing Mueller, starts to look like obstruction of justice. That would be grounds for impeachment."