As a federal prosecutor, Rudy Giuliani sent a congressman to jail, locked up mobsters and perp-walked Wall Street bankers. As mayor of New York City, he made the streets safe. After 9/11, he reassured a frightened city.

But ambition and hard living got the better of him.

His appearance in the second Borat movie four years ago, shoving his hands down his pants in a hotel room, is an image best forgotten – but very hard to actually forget. His work as Donald Trump’s personal lawyer lingers too. After Trump’s defeat in 2020, as Giuliani pushed the voter fraud lie under lights and cameras, hair dye ran down his face. Another scene for the ages.

Disgraced and disbarred, Giuliani stands criminally indicted in Georgia (with Trump) and Arizona too. In Manhattan, a federal judge recently ordered Giuliani to hand valuables and his Upper East Side penthouse to Ruby Freeman and Shaye Moss, Georgia election workers he defamed. The former mayor owes the two women $150m – and still he rants and raves. Last week at Madison Square Garden, at Trump’s hate-fest rally, Giuliani was just another warm-up act.

This week, seven days before election day, Giuliani published The Biden Crime Family. Another stab at relevance, it is less a book than an opposition research dump gone awry, another reminder of its author’s shambolic descent. It was written for a different presidential race, the one that existed until Joe Biden withdrew in July. Months later, here it is. Hapless is as hapless does.

There is some autobiography, inevitably interesting given Giuliani’s picaresque career. He revels in his past triumphs as a federal prosecutor – but in doing so, burns Trump again.

A rehash of the 1986 trial of Stanley Friedman starts off with a description of the “very powerful – and very corrupt – boss of the Democratic party in New York’s Bronx borough” who Giuliani set out to take down. So far, so good.

“He was a lobbyist who got people hired, then used that influence to get what he wanted. At the time, he wielded a great deal of power within New York Mayor Ed Koch’s city hall government.” Still good.

But here’s the thing: as reported by CBS in 2016, during cross-examination Rudy highlighted Friedman’s relationship with Roy Cohn – then Trump’s personal lawyer and fixer, the role Giuliani would later hold himself.

Giuliani: “And you told us during your direct examination, Mr Friedman, that during the latter part of time that you were deputy mayor, you had meetings with Roy Cohn and talked about joining his law firm; isn’t that correct?

Friedman: “Roy Cohn told me sometime prior to [that], ‘When you leave government, if you are ever interested in coming with my firm, let’s talk, and I’m interested in you.’ Words to that effect.”

Giuliani: “Now, isn’t it a fact that in your last week to 10 days in office, you signed for the very profitable deals with one of Roy Cohn’s major clients, Donald Trump – multi-million-dollar deals? You signed while you were deputy mayor, and you were going to his law firm a couple of days, if not a week later? … You knew that Donald Trump was a client of Roy Cohn … You knew he was a client of the law firm that you were about to join, a couple of days later?”

Friedman: “Yes, I did.”

Game, set, match. Friedman got 12 years.

Decades later, awaiting his own courtroom fate, Giuliani attributes his legal problems and those of Trump to persecution by “a fascist regime”. Practically speaking, the F-word is not one Giuliani should be dropping right now, and not just because John Kelly, Trump’s former chief-of-staff, recently called Trump a fascist.

Back in 2000, the Village Voice published an examination of Giuliani’s family history by Wayne Barrett, the great investigative reporter and biographer of both Giuliani and Trump. Barrett described conversations round the Giuliani dinner table during the second world war. Harold Giuliani, Rudy’s father, was there, rather than at the front – because he was a mob enforcer and stick-up guy who’d done time in Sing Sing, and was therefore not the kind of guy Uncle Sam wanted in uniform.

As Barrett wrote of Rudy’s mom, meanwhile, “The fact that their homeland was an Axis country did not diminish Helen Giuliani’s sense of patriotism. ‘She liked Mussolini and things like that,’” recalled Anna, Rudy’s aunt.

There’s more – though not, of course, in Giuliani’s new book. In 1989, amid Giuliani’s first campaign for mayor, news broke of a concentration camp survivor, Simon Berger, attending Giuliani’s office for questioning, only to be forced to sit near a blackboard bearing the message “Arbeit Macht Frei”, the slogan on the gates of Auschwitz. Alleging “Nazi tactics”, Berger was acquitted.

As Giuliani now writes: “I’m going to quote my good friend Steve Bannon, who always says, ‘There are NO conspiracies but there are NO coincidences.’”

Giuliani’s book was released on Tuesday – the day Bannon was himself released from prison after serving four months for contempt of Congress. Bannon gives Giuliani a foreword. It lacks the fire and fury of past pronouncements by Trump’s former White House strategist. Calling Giuliani a “brilliant lawyer”, Bannon concludes: “It will be clear to any American, after reading this book, that the Biden family … and even non-blood-related close allies – are a threat to the United States.”

To repeat: Biden hasn’t been a candidate for re-election for three months and more.

Still, none of these folks are prepared to leave the stage. Four years ago, Trump pardoned Bannon on fraud and conspiracy charges. In December, Bannon will go on trial in New York, in connection with an alleged border wall scam. It’s a state case, so no presidential pardon is possible. Elsewhere, Trump and Giuliani face their own felony indictments. Next week’s election will do much to determine how long either stays free.

• The Biden Crime Family is published in the US by War Room Books