Confidence Man: The Making of Donald Trump and the Breaking of America by Maggie Haberman:
Trump offered different explanations for Comey’s removal throughout the week. Initially the White House tried to paint the firing as coming at the recommendation of Rosenstein. In a private meeting with Russia’s foreign minister and ambassador, Trump volunteered that he had removed the “nut job” Comey and that doing so relieved “great pressure.” Then Trump gave an interview to NBC News anchor Lester Holt, during which he seemed to connect the firing to the Russia investigation. “In fact when I decided to just do it, I said to myself, I said, ‘You know, this Russia thing with Trump and Russia is a made-up story, it’s an excuse by the Democrats for having lost an election that they should have won,’ ” he said. But Trump’s answer was so clunky and at times incoherent that it wasn’t entirely clear that he was intending to say the investigation was the reason for the dismissal.
Comey’s firing set in motion a series of events that overwhelmed Trump’s presidency for the next two years. A week later, my colleague Michael Schmidt revealed that Comey had drafted a slew of secret memos about his encounters with the president, including the one in which Trump had indicated that Comey should end the Flynn investigation. It swiftly changed the view of Trump’s intentions among Democrats, media, and some Justice Department officials. With that pressure bearing down, in place of the recused Sessions, Rosenstein—who was not a Trump loyalist—named a special counsel to investigate not only the possibility of conspiracy between Russians and the Trump campaign, but whether Trump had attempted to obstruct the investigation by firing Comey.