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"Tell-all" books from inside Donald Trump’s administration have come in all shapes and sizes. There are the unshakably loyal, bordering on sycophantic - such as the one from Sean Spicer, the former White House press secretary who remains a favoured son.
There are the strait-laced with hints of criticism, from career public servants like Jim Mattis, the ex-defence secretary, and his Pentagon aide Guy Snodgrass.
There have been ones with a spiky edge, like former Apprentice star turned sacked White House aide Omarosa Manigault and some even hit their target, like the ex-FBI director James Comey and his revelations about 'Russiagate'. Yet the former was a peripheral figure and the latter was never a Trump man.
And there is John Bolton’s new book - an exocet missile fired by someone hand-picked by the president so damning in its claims it could cause untold political damage.
Exactly what lies on each of the 592 pages of Mr Bolton’s book is not yet known. It is not out until Tuesday, or possibly later should the Trump administration's scrambled legal attempts to stop its release have some success.
But enough is already available, thanks to leaked copies obtained by three US newspapers and unpacked in wincing detail, to know what the man who just 10 months ago was Mr Trump's top national security adviser will claim.
Almost no aspect of the 45th US president goes uncriticised - his temperament, his motives, his mental faculty, his moral compass, his understanding of government, diplomacy and policy-making.
Mr Trump is at times portrayed as self-centred, domineering and pig-headed and yet also as a man awed by the office, unsuited to its responsibilities and unable to put the country first.
“He second-guessed people’s motives, saw conspiracies behind rocks, and remained stunningly uninformed on how to run the White House, let alone the huge federal government,” Mr Bolton writes in one especially damning line.
Most destructive of all are the allegations - and it should be remembered they are only that, claims of a former employee and not independently substantiated - from inside the room with Mr Trump.
There is the scene with Xi Jinping, the Chinese president, where Mr Trump floats the bulk-buying of US agricultural goods by Beijing as a way of helping his re-election chances. Farmers are key voters in some battleground states.
Mr Trump has just endured impeachment for urging one foreign leader, the president of Ukraine, to do something that would help his election hopes (investigating his rival Joe Biden). Here, allegedly, is evidence of another.
Or the meetings with Kim Jong-un, the North Korean leader. Mr Trump is not bothered with issuing a “substance-free communiqué” after one summit, Mr Bolton recalls. The president cared little for the details of denuclearisation and saw the meeting as “an exercise in publicity”, he claims.
He did have one keen interest, however - ensuring that an autographed Elton John CD of the song Rocket Man - his nickname for Kim - was given to his counterpart. It was “a high priority for several months”, Mr Bolton writes. There are too many stories like this to recount - at least 20 specific anecdotes that have already emerged from the book which paint Mr Trump, to put it mildly, in a negative light. Mr Trump's full response to the claims is not known but a firm blanket denial is expected.
The key question, then, is so what? What impact will these stories actually have? It is too late for another impeachment drive. Mr Bolton missed his chance by refusing to speak publicly during the last one.
Plus every possible view of the president is already baked into the electorate, many strategists argue. Those who dislike Mr Trump will recoil in horror at the revelations; those firmly with him will see a hit job.
A deluge of discrediting attacks is surely coming Mr Bolton’s way. He is already being dragged through the courts, dubbed "Book Deal Bolton" and threatened with criminal proceedings by the president.
But could the revelations actually break through? Could they nudge some of those reluctant Trump voters, the ones in the suburbs and the all-important swing states, into the Biden column?
Mr Bolton is not a Democrat. He is not a "deep state" civil servant. He is a Republican heavyweight - if a controversial one - selected by Mr Trump himself to hold one of his administration’s most senior jobs.
Either way, voters will not be able to ignore it. The claims are already playing out on every national TV news channel and newspaper website in America.
The most devastating portrait of this president by a former adviser is now being seen, in the brightest of lights, less than 150 days before the election.
And the Bolton interviews have not even begun airing yet.