It took just two weeks and 1,000 words for the cesspit which is Donald Trump’s administration to consume the reputation of Rod Rosenstein.

The Jewish lawyer had been in his job as America’s Deputy Attorney General barely a fortnight when he penned the now infamous memorandum that provided the ammunition with which the president fired the former Director of the FBI, James Comey.

Mr Trump has now dropped the pretence that Mr Comey was sacked for his mishandling of the investigation into Hillary Clinton’s emails detailed in Mr Rosenstein’s three-page indictment. In so doing, the Deputy Attorney General – who is supposed to be overseeing the FBI’s investigation into links between the Trump campaign and Putin’s henchmen – stands accused of aiding and abetting an attempt to whitewash the Trump administration’s dirty Russia laundry.

Until last week, Mr Rosenstein’s had an unimpeachable reputation as a straight up straight-shooter. Over three decades he has worked as a government lawyer serving under the administrations of both Republican and Democrat presidents. In 2005, he was appointed US attorney for Maryland by George W Bush, where he burnished his reputation for tackling police corruption. Four years later, he was one of only three US attorneys – out of a total of 93 – to be kept in place by the incoming Obama administration. Indeed, he was the only US attorney appointed by Mr Bush to serve for all eight years of Barack Obama’s presidency.

While politically to the right – he joined the conservative Federalist Society at Harvard Law School – Mr Rosenstein even managed to emerge from the drummed-up investigations into Bill Clinton with his squeaky-clean image intact. Despite being a member of Special Prosecutor Ken Starr’s team of muck-raking lawyers, Mr Clinton’s Deputy Attorney General later said of Mr Rosenstein: “I would have trusted him with anything.” As the Washington Post noted in a 2011 profile of him: “Even courtroom adversaries talk about the career prosecutor as if he were the real-life version of a Jimmy Stewart character.”

Unsurprisingly, unlike most of Mr Trump’s other nominees, Mr Rosenstein’s appointment as Deputy Attorney General sailed through the Senate: he was confirmed by 96 votes to four. After Attorney General Jeff Sessions was forced to recuse himself from the investigation into Mr Trump’s ties to the Kremlin, having been caught lying to the Senate about his own actions during the campaign, Democrats breathed a sigh of relief that the probe would fall under Mr Rosenstein’s remit.

No more, however. The Deputy Attorney General’s evident unease at the turn of events – he has denied media reports that he threatened to resign over initial White House claims that Mr Trump acted solely on his advice – has not dampened the Democrats’ fury. Only by agreeing to their demands to appoint an impartial Special Prosecutor can Mr Rosenstein both begin to repair his own tattered reputation and, quite possibly, protect the US Constitution from Mr Trump’s determination to trample it under foot. In the wake of Mr Trump’s election six months ago, another principled Jewish conservative, Eliot Cohen, recommended those considering serving in the new administration to think again. Mr Rosenstein’s fate should serve as a warning to all those who failed to do so.