During a segment on CNN, political analyst Jeffrey Toobin called FBI Director James Comey's sudden firing from his post by President Donald Trump “a grotesque abuse of power by the president of the United States.”

“This is the kind of thing that goes on in non-democracies,” Toobin told CNN host Wolf Blitzer.

Toobin went on to say that Comey’s firing is reminiscent of President Nixon firing Archibald Cox, the special prosecutor in the Watergate investigation.

“This is something that is not within the American political tradition,” Toobin said. “This is something that is completely outside how American law is supposed to work.”

In his letter to Comey, President Trump thanked him for his service, and included a remark about personal reassurances the former FBI director gave the president.

“While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgment of the Department of Justice that you are not able to effectively lead the Bureau,” Trump wrote in Comey’s termination notice, which has been acquired by journalists.

Watch Toobin discuss the Comey firing below, via CNN.