The NY Times got hold of the new book by Trump’s nephew. It’s exactly what you would expect: In 2020, a few months before the last election, former President Donald J. Trump’s niece, Mary Trump, published a book about her uncle and how awful and psychologically warped she found him to be. At the time, her brother, Fred C. Trump III, put out a statement slamming his sister for such treachery. Now, he’s wielding the knife. Next week, he will publish “All in the Family: The Trumps and How We Got to Be This Way,” a tell-all that puts the former president in a harsh light. The New York Times obtained a copy. Fred isn’t like his sister Mary. He was upset about her hostility and remained fairly close to his uncle even visiting from time to time at the White House where Trump would brag about how he killed terrorists. But the relationship soured because of this: Fred Trump’s son was born with a rare medical condition that led to developmental and intellectual disabilities. His care had been paid for in part with help from the family. After Mr. Trump was elected, Fred Trump wanted to use his connection to the White House for good. With the help of Ivanka Trump, his cousin, and Ben Carson, at the time the housing and urban development secretary, he was able to convene a group of advocates for a meeting with his uncle. The president “seemed engaged, especially when several people in…