A New York judge ruled on Monday that Mary L. Trump, the niece of President Trump, could legally go ahead with the publication of her explosive tell-all memoir about her famous family, ending a whirlwind of last-minute litigation to try to stop the book.
The decision by the judge was largely a symbolic victory, given that it came on the eve of the official release of the book, “Too Much and Never Enough: How My Family Created the World’s Most Dangerous Man,” which is already in print and has received enormous public attention.
The memoir reveals what Ms. Trump has described as a number of family secrets, including an allegation that as a young man Donald J. Trump paid someone to take his college entrance exams on his behalf. It also describes how Mr. Trump’s sister, Maryanne Trump Barry, a former federal judge, considered him “a clown” who had “no principles.”
Last week, Kayleigh McEnany, the White House press secretary, said the book was filled with “falsehoods.”
The fight over the book began last month, when the Trump family, led by Robert S. Trump, the president’s younger brother, sought to enjoin Ms. Trump and her publisher, Simon & Schuster, from releasing it, arguing that a confidentiality agreement she signed nearly 20 years ago forbade her from revealing family secrets. The secrecy pact was agreed to as part of a settlement of a group of long-simmering disputes concerning the will of the family patriarch, Fred Trump Sr., the president’s father and Ms. Trump’s grandfather.
In his ruling on Monday night, Judge Hal B. Greenwald of State Supreme Court in Dutchess County, N.Y., said that the confidentiality agreement could not be used to stop Ms. Trump or Simon & Schuster from publishing the book because the secrecy provision was narrowly tailored to the disagreements about the will, not about any subject related to the Trumps.
“Why would a 2001 settlement of two estate matters and a local Supreme Court case contain a clause prohibiting the parties to these actions to ever speak again about their relationships?” Judge Greenwald wrote.
He also noted that since the book was already in print and would go on sale Tuesday morning, Simon & Schuster would face “immense costs” if publication were to be stopped. Judge Greenwald said the public had a right to hear Ms. Trump’s stories about what she called her dysfunctional family.
“The Trumps were local in 2001,” Judge Greenwald wrote, referring to the year when the confidentiality agreement was reached. “The leader of the Trump family in 2020 is global.”
Charles Harder, a lawyer for Robert Trump, did not immediately respond to an email seeking comment.
But in a statement released on Monday night, a spokesman for Ms. Trump said, “The White House and America are looking forward to finally hearing what Mary has to say.”
Theodore J. Boutrous Jr., Ms. Trump’s lawyer, also issued a statement, saying that Judge Greenwald had ruled correctly in the case.
“The First Amendment forbids prior restraints because they are intolerable infringements on the right to participate in democracy,” Mr. Boutrous said. “Tomorrow, the American public will be able to read Mary’s important words for themselves.”
Simon & Schuster also praised Judge Greenwald’s ruling.
“The unfettered right to publish is a sacred American freedom and a founding principle of our republic,” the publisher wrote in a statement. “We applaud the court for affirming well-established precedents against prior restraint and pre-publication injunctions.”