By LUCIEN BRUGGEMAN, NADINE SHUBAILAT and JOHN SANTUCCI, ABC News

(NEW YORK) — A much-anticipated memoir penned by President Donald Trump’s niece offers a personal and damning account of the rise of the man who now occupies the Oval Office, according to a copy of the forthcoming book obtained by ABC News.

Over the course of 210 pages, Mary Trump, the daughter of the president’s deceased elder brother, Fred Trump Jr., inserts several private and embarrassing anecdotes into the broadly known narrative of President Trump’s life, details of which are sure to embolden his critics and enrage his allies.

Mary Trump’s account is unabashedly tied to the current political climate. With less than four months until the 2020 election, the president’s niece warned, “If he is afforded a second term, it would be the end of American democracy.”

The book, titled, Too Much and Never Enough: How My Family Created the World’s Most Dangerous Man, has emerged as the latest behind-the-scenes glimpse into the controversial leader. After weeks of legal jockeying, publisher Simon & Schuster announced this week that it would release the book on July 14 — two weeks earlier than planned — due to “high demand and extraordinary interest.”

Based in part on personal memories and conversations with family members, according to an author’s note, Mary Trump, a trained psychologist, wrote that she “also relied on legal documents, bank statements, tax returns, private journals, family documents, correspondence, emails, texts, photographs, and other records.”

“No one knows how Donald came to be who he is better than his own family. Unfortunately, almost all of them remain silent out of loyalty or fear. I’m not hindered by either of these,” Mary Trump wrote in her prologue. “I hope this book will end the practice of referring to Donald’s ‘strategies’ or ‘agendas,’ as if he operates according to any organizing principles. He doesn’t.”

In Mary Trump’s telling, the president’s worldview was shaped at a young age by his father, Fred Trump Sr. — her grandfather — whom she called “a high-functioning sociopath” and served “to encourage Donald’s reckless hyperbole and unearned confidence that hid Donald’s pathological weaknesses and insecurities.”

Near the end of his father’s life, Mary Trump claimed that the vast family estate became a battleground for Trump and his siblings. She accused him of coming up “with a plan to betray his father and steal vast sums of money from his siblings.”

“He secretly approached two of my grandfather’s longest-serving employees [a lawyer and accountant], and enlisted them to draft a codicil to my grandfather’s will that would put Donald in complete control of Fred’s estate, including the empire and all its holdings, after he died,” she wrote.

Mary Trump wrote that her aunts and uncle were suspicious, and that her grandfather refused to sign off on the change when Trump approached him — adding her grandmother said, “it simply didn’t pass the smell test.”

The real financial battles did not occur until after Fred Trump Sr. died in 1999. According to Mary Trump, her grandfather had revised his will to essentially disinherit her and her brother — “instead of splitting what would have been my [late] father’s 20 percent share of his estate between me and my brother, he had divided it evenly among his four other [living] children,” leaving her and her brother a relatively small inheritance equivalent to those given the other grandchildren. When they sought legal action, Mary Trump wrote, the family in turn got spiteful, taking away medical insurance that they had had for their entire lives through their grandfather’s company.

“It was merely a way to cause us more pain and make us more desperate,” she wrote. The family eventually settled, according to Mary Trump, who claimed the value of their settlement should have been much larger as her settlement was based on an undervalued estimate of the total estate.

Mary Trump also notes in the book that she was a source of information provided to the New York Times regarding her uncle’s tax returns, which showed Trump’s businesses were in the red throughout the 1980s and 1990s, at times hemorrhaging tens of millions of dollars, according to the Times report, which was based on IRS tax transcripts from 1985 to 1994.

Mary Trump also wrote that she briefly worked for the president’s company, The Trump Organization, in the mid-1990s and was shortly hired by him to specifically assist him with writing his third memoir, The Art of the Comeback, although she was soon replaced. She also claimed that while she was wearing a bathing suit during a visit to Mar-a-Lago, Trump commented “Holy s—, Mary. You’re stacked!” Which led Marla Maples, then Trump’s second wife, to slap him lightly on the arm, according to Mary Trump’s account in the book.

During the summer of 2015, when he announced his bid for the presidency, Mary Trump wrote that she “didn’t take it seriously.” The family overwhelmingly felt it was a business-minded stunt, according to the book.

“‘He’s a clown,’ my aunt Maryanne said during one of our regular lunches at the time,” Mary Trump wrote. “‘This will never happen.’ I agreed. We talked about how his reputation as a faded reality star and failed businessman would doom his run. ‘Does anybody even believe the bulls— that he’s a self-made man? What has he even accomplished on his own?’ I asked. ‘Well,’ Maryanne said, as dry as the Sahara, ‘he has had 5 bankruptcies."”

On the campaign trail, when Trump made overtures to the evangelical community, his sister scoffed, Mary Trump wrote.

“Maryanne, a devout Catholic since her conversion 5 decades earlier, was incensed,” according to the book. “‘What the f— is wrong with them?’ she said. ‘The only time Donald went to church was when the cameras were there. It’s mind boggling. He has no principles. None!"”

As president, Mary Trump concluded, the culmination of his experiences in family and professional life has led to his “aberrant behavior” in office.

“Donald is completely unprepared to solve his own problems or adequately cover his tracks,” she wrote. “Donald’s checkered personal history and his unique personality flaws make him extremely vulnerable to manipulation by smarter, more powerful men.”

Lawyers for the president’s younger brother, Robert Trump and Judge Maryanne Trump Barry did not immediately respond to ABC News’ request for comment. The White House also did not respond to an ABC News request.

For his part, President Trump has previously said his niece is “not allowed to write a book,” telling Axios last month that she signed a “very powerful” nondisclosure agreement that “covers everything” as it relates to her settlement with the family estate.

Robert Trump filed suit against Mary Trump and Simon & Schuster two weeks ago seeking to block the book’s publication on the grounds that it would violate a nondisclosure agreement Mary Trump signed when she settled her lawsuit over her grandfather’s will. A New York appellate judge held that Simon & Schuster could not be barred from releasing the book. A hearing on the restraining order against Mary Trump is scheduled to take place on Friday.

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