(Bastien Inzaurralde/The Washington Post)

Former aides to Hillary Clinton expressed a combination of disbelief and outrage over President Trump’s firing of FBI Director James Comey on Tuesday night, suggesting that the move was an attempt by Trump to frustrate the ongoing investigation into his campaign’s ties to Russia.

Trump fired Comey, citing the need for “new leadership” that can restore “public trust and confidence” in the agency. A second, longer letter written by Deputy Attorney General Rod J. Rosenstein specifically highlights Comey’s handling of the FBI’s investigation into Clinton’s use of a private email server as secretary of state.

But far from elating Clintonworld — which has long argued that Comey mishandled the investigation — the decision opened a floodgate of calls among shocked Democrats across the party for an independent probe into the Trump campaign.

“Twilight zone. I was as disappointed and frustrated as anyone at how the email investigation was handled. But this terrifies me,” Clinton’s former campaign manager, Robby Mook, wrote on Twitter. “Surprised I’m saying this, but I don’t see how this bodes well for the Russia investigation.”

Moving quickly past their surprise, Democrats have responded almost in unison, dismissing the firing of Comey as an attempt to stymie the Russia investigation. Former Clinton aides, Democratic Party officials and lawmakers called the move “Nixonian,” suggesting that it has made the need for an independent probe all the more critical.

(Victoria Walker/The Washington Post)

“Donald Trump’s firing of James Comey is a brazen and disgraceful abuse of power,” Democratic National Committee Chairman Thomas Perez, who was a surrogate for Clinton during the campaign, said in a statement. “The fact that the leadership of the Justice Department was complicit in manufacturing this joke of a rationale for Comey’s dismissal at the request of Trump is further evidence that nobody in this Administration can be trusted to lead an honest investigation into a serious national security issue.

“It is time for leaders in both parties to come together and call for the appointment of a special prosecutor at the Department of Justice and an independent commission to conduct the kind of investigation that the American people deserve,” he added.

Citing Comey’s actions in the July news conference on the email investigation and leading up to the election as the rationale, Trump is now in the unusual position of firing the FBI director for actions that his critics say made him president.

At the same time, Clinton’s allies characterized Trump’s stated rationale as the pretext for a different political motivation.

“Really, he’s doing it to get out from under the Russia investigation,” former Clinton aide Brian Fallon said on CNN. “The only thing that can happen now is we need a special counsel inside the Justice Department.”

Sen. Bernie Sanders (I-Vt.), who challenged Clinton in the Democratic primaries, also suggested that the person who replaces Comey at the FBI would not have credibility to continue the Russia investigation.

“President Trump has repeatedly taken steps to kill inquiries into Russia’s involvement in the U.S. election,” Sanders said in a statement. “It is clear that whomever President Trump handpicks to lead the FBI will not be able to objectively carry out this investigation.

Former Hillary Clinton campaign manager Robby Mook, shown here with communications director Jennifer Palmieri in Iowa in October, tweeted Tuesday that President Trump’s firing of FBI director James Comey “terrifies” him. (Melina Mara/The Washington Post)

“We need an independent investigation into the Trump campaign’s ties to Russia,” he added.

Comey’s abrupt dismissal came just hours after the FBI submitted a letter to Congress correcting the director’s testimony during a hearing last week, in which he incorrectly stated that “hundreds and thousands” of emails from Clinton aide Huma Abedin had been forwarded to the computer of her estranged husband Anthony Weiner. In fact, Abedin forwarded only two emails, and the remainder were automatically backed up on Weiner’s computer from her BlackBerry device.

But Rosenstein’s letter — the most detailed of the documents released by the White House about Comey’s dismissal — strongly criticizes the former director for his actions at a July 2016 press conference, where he revealed that Clinton would not be charged with a crime. At the same event, Comey chastised Clinton for her handling of classified information, which Rosenstein called a “textbook example of what federal prosecutors and agents are taught not to do,”

Then Comey released a letter 11 days before the election telling Congress that the FBI was examining new emails as part of its probe into the Clinton email matter, only to announce more than a week later that the emails turned out to be immaterial. Clinton and many of her allies have cited the initial letter as the catalyst for her loss to Trump.

In a congressional hearing before the Senate Judiciary Committee last week, Comey defended his decision.

“Look, this is terrible. It makes me mildly nauseous to think that we might have had some impact on the election,” Comey said. “But honestly, it wouldn’t change the decision.”

Clinton’s former aides said that while they agree that Comey acted inappropriately throughout the investigation, Trump’s actions are suspicious.

“I think Comey and the FBI mishandled the investigation around the emails from at least July of 2016 on, concluding with the misrepresentation about Huma last week,” Jennifer Palmieri, Clinton’s former communications director, said in an interview on Tuesday. “I’m suspicious that this has more to do with the FBI’s investigation of Trump than Clinton.”

Adding to the concern for Clinton’s aides is Trump’s letter to Comey, in which he specifically offered gratitude to Comey for his repeated confirmation that Trump was not personally under investigation.

“I am no Comey fan, but POTUS firing FBI Director conducting investigation into campaign is indefensible,” Glen Caplin, a former spokesman for Clinton, wrote on Twitter. “Need independent investigation ASAP.”