"I think that his credibility is really at hand, and it's quite interesting that he would question someone else's when he has such a lack of credibility himself", Sanders said.
"A person who sees moral equivalence in Charlottesville, who talks about and treats women like they're pieces of meat, who lies constantly about matters big and small and insists the American people believe it; that person's not fit to be president of the United States, on moral grounds", Comey said, citing last year's white nationalist rally in Charlottesville, Virginia.
Comey says that in his view a president must embody respect and adhere to the nation's core values, the most important being truth. "Lot more flexibility there", Comey said, adding that "they're still required to tell the truth".
Detailed accounts of Comey's impressions on Trump and his presidency are articulated in his book, "A Higher Loyalty".
In the one-on-one meeting, Comey says, Trump seemed to suggest that Comey should stop the FBI's investigation into Michael Flynn, the former national security adviser, related to his communications with Russians. An agency where his deputy director appeared to leak information to the press - sound familiar Comey? - and then lied about it to his boss, to FBI investigators while under oath and to the Justice Department inspector's general. Asked whether Mr Comey was a man of integrity, the Republican speaker said: "As far as I know", but added that he did not know him well. 'Why am I alone if he doesn't know the nature of the request?' Mr. Comey said.
During the interview, Stephanopoulos asked Comey what it would "mean if President Trump tries to fire Robert Mueller". Comey, Trump tweeted, "was making decisions based on the fact that he thought she was going to win, and he wanted a job".
None of those utterances, however, was as telling as what Comey said after Stephanopoulos reminded him that the president had called him a liar.
Excerpts have already been widely reported, prompting President Donald Trump and his conservative allies to launch a furious attack on Comey.
JAMES COMEY: My impression was he looked exactly like he did on television, except he looked shorter to me than he did on television, but otherwise exactly the same. President, I can't discuss this. "I think it's possible".
Trump and the Republicans have sought to stifle the impact of his book by accusing Comey of leaking classified materials and of corruptly handling the 2016 investigation into Clinton. Comey served as the seventh director of the Federal Bureau of Investigation from September 4, 2013, until he was sacked on May 9, 2017. Comey said he chose to confirm the Clinton email case because it "began with a public referral" and "we were actually investigating the candidate herself", but he declined to publicly discuss the Trump counterintelligence investigation before the election because Trump wasn't a target, "we didn't know what we had, and we didn't want to tip them off that we were looking at them".
So partly for that reason, he said, he chose to announce on his own his recommendation that no charges be filed in the Clinton case.