It’s come to this: James Comey, the former head of the F.B.I., says that the President of the United States operates like a mob boss—lying, scheming, and demanding loyalty oaths from his subalterns, with no regard for morality. In response, the President has called the former G-man a “weak and untruthful slime ball.”

Thus begins the publicity cycle for James Comey’s new book, “A Higher Loyalty: Truth, Lies, and Leadership.” Although the tome doesn’t officially come out until next week, a number of media outlets published extensive accounts of its contents on Thursday and Friday. The Times even published an early review, in which Michiko Kakutani describes Comey’s work as “absorbing” and compares him to both Eliot Ness, the federal agent who helped bring down Al Capone, and Will Kane, the town marshal Gary Cooper plays in “High Noon.” That is the narrative that the White House is trying to counter, of course. “James Comey is a proven LEAKER & LIAR. Virtually everyone in Washington thought he should be fired for the terrible job he did-until he was, in fact, fired,” Trump wrote in the first of two seething tweets on Friday morning. In the second tweet, he rolled out his “slime ball” line and described Comey’s handling of the Hillary Clinton e-mail investigation as “one of the worst ‘botch jobs’ in history.” Simultaneously, one of Trump’s aides, Kellyanne Conway, went on television and sought to dismiss Comey as a “disgruntled former employee.”

As Trump demonstrated during the 2016 campaign, insulting people is one of the few things for which he possesses a genuine talent. But in this case, he is facing a mighty challenge. “A Higher Loyalty” contains detailed accounts of Comey’s personal dealings with Trump and the people around him, including Attorney General Jeff Sessions and the former White House chief of staff Reince Priebus. While some of this material is familiar from the testimony that Comey gave to the Senate Intelligence Committee last June, the book contains many new details—yes, the notorious rumored “pee tape” is discussed—as well as the former F.B.I. chief’s personal reflections about Trump, which are damning.

Back in the late eighties and early nineties, long before he occupied the director’s suite at the J. Edgar Hoover Office Building, on Pennsylvania Avenue, Comey worked in the office of the U.S. Attorney for the Southern District of New York. There he helped prosecute the Gambino crime family, headed by John Gotti, in cases that were largely based on the wiretapping of Gotti’s hangouts, such as the Ravenite Social Club, on Mulberry Street, along with evidence provided by Sammy (the Bull) Gravano, a Gambino underboss who coöperated with prosecutors and confessed to being involved in nineteen murders.

Referring to his one-on-one dinner with Trump on January 27, 2017, during which the new President told him, “I need loyalty, I expect loyalty,” Comey recalls that it brought him right back to “The Ravenite. The Palma Boys. Café Giardino.” He writes, “To my mind, the demand was like Sammy the Bull’s Cosa Nostra induction ceremony—with Trump in the role of the family boss, asking me if I have what it takes to be a ‘made man’.”

The comparison between the Trump White House and an organized-crime family doesn’t end there. Comey recounts two more White House meetings that also left him feeling compromised. At a White House meeting that was attended by representatives of the intelligence agencies, Trump and his political advisers instigated a discussion about how to respond to the charges against Trump in the infamous dossier compiled by the former British spy Christopher Steele. “Holy crap,” Comey writes, “they are trying to make each of us an ‘amica nostra’—a friend of ours. To draw us in. As crazy as it sounds, I suddenly had the feeling that, in the blink of an eye, the president-elect was trying to make us all part of the same family.”

On another occasion, in February, 2017, Reince Priebus, Trump’s obsequious chief of staff, took Comey into the Oval Office, where Trump delivered a “stream of consciousness” monologue about an interview he had given to Bill O’Reilly, of Fox News, and sought his visitor’s approval of the performance. When Comey said something that Trump took as less than a glowing tribute, the President’s stare hardened, and Priebus quickly led Comey out. “The encounter left me shaken,” he writes. “I had never seen anything like it in the Oval Office. As I found myself thrust into the Trump orbit, I once again was having flashbacks to my earlier career as a prosecutor against the mob. The silent circle of assent. The boss in complete control. The loyalty oaths. The us-versus-them worldview. The lying about all things, large and small, in service to some code of loyalty that put the organization above morality and the truth.”

Priebus isn’t the only Trump associate who comes off looking bad. As he did during his Senate testimony last year, Comey describes an Oval Office meeting that took place on February 14, 2017, at which the President asked Jeff Sessions, the Attorney General, to leave the room so he could speak to Comey alone, and then proceeded to ask the F.B.I. director if he could let off Michael Flynn, his former national-security adviser. For the first time, Comey then relates how he confronted Sessions after the meeting, saying, “You can’t be kicked out of the room so he can talk to me alone. You have to be between me and the president.” In response, Comey writes, “Sessions just cast his eyes down at the table, and they darted quickly back and forth, side to side. He said nothing. I read in his posture and face a message that he would not be able to help me.”

This vignette illustrates Comey’s central point: Trump is Trump. “This president is unethical, and untethered to the truth and institutional values. His leadership is transactional, ego driven, and about personal loyalty,” Comey notes in his epilogue. But Trump has always been like that, and little more could have been expected of him. The larger tragedy of Trump’s Presidency, Comey argues, is how it has corrupted those around him and degraded the U.S. political system at large: “We are experiencing a dangerous time in our country with a political environment where basic facts are disputed, fundamental truth is questioned, lying is normalized and unethical behavior is ignored, excused or rewarded.”

Although he doesn’t name all the people to blame for this sorry state of affairs, Comey leaves no doubt that responsibility rests with Trump’s enablers in the political organization that Comey himself used to support: the Republican Party. (These days, Comey identifies himself as an independent.) When the former F.B.I. director writes that it is “wrong to stand idly by, or worse, to stay silent when you know better, while a president brazenly seeks to undermine public confidence in law enforcement institutions that were established to keep our leaders in check,” there can be no doubt of his intended targets.

With the Republican National Committee’s new “Lyin Comey” Web site, the Party’s media outriders at Fox News and elsewhere, and the tweets of the Commander-in-Chief, Trump and his circle will do all they can to discredit Comey in the coming days. But Trump’s approval ratings and the recent elections in Virginia and Pennsylvania suggest that the majority of the American public has already taken Comey’s message to heart, because it is so obviously true: “What is happening now is not normal. It is not fake news. It is not okay.”