WASHINGTON (NYTIMES) - In dramatically casting aside Mr James Comey, US President Donald Trump fired the man who may have helped make him president - and the man who potentially most threatened the future of his presidency.
Not since Watergate has a president dismissed the person leading an investigation bearing on him, and Mr Trump's decision late Tuesday afternoon (May 9) drew instant comparisons to the Saturday Night Massacre when President Richard M. Nixon ordered the firing of Mr Archibald Cox, the special prosecutor looking into the so-called third-rate burglary that would eventually bring Mr Nixon down.
In his letter informing Mr Comey that he was terminated as FBI director, Mr Trump made a point of noting that Mr Comey had three times told the president that he was not under investigation.
But Mr Comey has said publicly that the bureau is investigating Russia's meddling in last year's presidential election and whether any associates of Mr Trump's campaign were coordinating with Moscow.
While Mr Trump said he acted on the recommendation of Attorney General Jeff Sessions, he had left little doubt about his personal feelings toward Mr Comey or that Russia investigation in recent days.
"Comey was the best thing that has ever happened to Hillary Clinton in that he gave her a free pass for her many bad deeds!" he wrote on Twitter a week ago.
"The Russia-Trump collusion story is a total hoax, when will this taxpayer funded charade end?" he added on Monday (May 8).
Some Democrats immediately raised the spectre of Watergate and called for a special counsel to lead an independent investigation into the Russian meddling and any ties to Mr Trump's campaign.
"This is Nixonian," Senator Bob Casey said in a statement.
"Not since Watergate have our legal systems been so threatened and our faith in the independence and integrity of those systems so shaken," added Senator Richard Blumenthal.
The paradox, of course, is that Mr Comey had few fans among Democrats, especially Mrs Hillary Clinton, who just last week blamed him for steering the election to Mr Trump by publicly announcing shortly before the election that he was reopening his investigation into her private e-mails.
Ever since Watergate, presidents have been reluctant to take on FBI directors, no matter how frustrated they were. The only exception was President Bill Clinton, who fired Mr William S. Sessions in 1993 after ethical issues were raised against him, and was accused of acting politically.
The successor he appointed, Louis J. Freeh, became even more of a headache for Mr Clinton as he helped independent counsel Kenneth W. Starr investigate the president.
But Mr Clinton never risked the political backlash that would have come had he dismissed Mr Freeh.
Robert S. Mueller III threatened to resign as FBI director during President George W. Bush's administration if a secret surveillance programme he considered illegal were continued, and Mr Bush backed down rather than risk the scandal that would have ensued.
Joining Mr Mueller in that threat, as it happened, was a deputy attorney general named James Comey.
Mr Timothy Naftali, a former director of the Richard M. Nixon presidential library, said Mr Trump's dismissal of Mr Comey was not a direct parallel to the Saturday Night Massacre because he was not appointed specifically to investigate the 2016 campaign.
"With or without Mr Comey, the FBI will continue to investigate the 2016 campaign as it relates to Russian intervention," Mr Naftali said.
"This is another kind of mistake. Unless Attorney General Sessions can prove malfeasance or gross negligence by Comey, the timing of this action further deepens suspicions that President Trump is covering up something."