President Trump fired James Comey, director of the Federal Bureau of Investigation, on Tuesday afternoon.

According to a letter from Trump that was reportedly hand-delivered to Comey’s office by Trump’s longtime top security aide, the president acted because Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein recommended that Comey be dismissed. Comey was in Los Angeles and reportedly learned of the news from the television.

In a letter to Trump, Sessions stated that “a fresh start is needed at the leadership of the FBI” and that he concurred with the reasoning of an attached memo by Rosenstein regarding Comey.

The Rosenstein memo stated that he “cannot defend the Director’s handling of the conclusion of the investigation of Secretary [Hillary] Clinton’s emails.”

“The Director was wrong,” Rosenstein wrote, “to usurp the Attorney General’s authority on July 5, 2016, and announce his conclusion that the case should be closed without prosecution. … Compounding the error, the Director ignored a longstanding principle: we do not hold press conferences to release derogatory information about the subject of a declined criminal investigation.”

That is, Trump is claiming that he fired Comey because the FBI director acted unfairly toward Clinton.

The reaction from Democrats toward Trump’s decision has been uniformly negative, with many now demanding that the Justice Department appoint a special prosecutor to oversee the ongoing counterintelligence investigation of the 2016 Trump campaign.

Sen. Pat Leahy, D-Vt., said that Comey’s firing was “nothing less than Nixonian.”

Rep. Steve Cohen, D-Tenn., also recalled the so-called Saturday Night Massacre in 1973 when top officials at the Justice Department resigned rather than carry out President Nixon’s demand that they fire a special prosecutor investigating the Watergate scandal. Cohen stated that “our democracy is in danger” and asked Speaker of the House Paul Ryan, R-Wis., to appoint a bipartisan commission to investigate “the Trump-Russia relationship.”

Several Republicans also appeared concerned by Trump’s actions. Sen. Richard Burr of North Carolina, chairman of the Senate Intelligence Committee, which is conducting an investigation into any ties between Trump and Russia, said that “I am troubled by the timing and reasoning of Jim Comey’s termination.”

Republican Sen. John McCain of Arizona stated that Comey’s firing “only confirms the need and the urgency” for a “special congressional committee to investigate Russia’s interference in the 2016 election.”

By contrast, Sen. Lindsay Graham, R-S.C., appeared sanguine about Comey’s removal:

White House counselor Kellyanne Conway appeared on CNN to defend the firing. When Anderson Cooper asked Conway why Trump fired Comey, despite having praised his treatment of the email investigation on the campaign trail, Conway responded that Cooper was “looking at the wrong set of facts.”

For its part, the Nixon Library tweeted, “FUN FACT: President Nixon never fired the Director of the FBI,” with the hashtag #notNixonian.