Hillary Clinton, in a chapter from her forthcoming book "Hard Choices," rails against congressional Republicans for politicizing the deadly attack on the American diplomatic facilities in Benghazi, writing that “I will not be a part of a political slugfest on the backs of dead Americans. It’s just plain wrong, and it’s unworthy of our great country."

Sources close to Clinton confirmed that an excerpt obtained by Politico was authentic. In it, Clinton gives a detailed account of the incidents surrounding the attack in a chapter entitled “Benghazi: Under Attack.”

“Those who exploit this tragedy over and over as a political tool minimize the sacrifice of those who served our country,” Clinton writes.

In a rebuttal to critics of National Security Adviser Susan Rice, who was U.S. ambassador to the United Nations when she told several news outlets in September 2012 that the attack was a “spontaneous reaction” to an anti-Muslim video on YouTube, Clinton writes that the video did play a role in the attacks.

“There were scores of attackers that night, almost certainly with differing motives,” she writes. “It is inaccurate to state that every single one of them was influenced by this hateful video. It is equally inaccurate to state that none of them were. Both assertions defy not only the evidence but logic as well.”

Clinton also addresses questions about rescue attempts at the compound, writing that Obama “gave the order to do whatever was necessary to support our people in Libya. It was imperative that all possible resources be mobilized immediately. … When Americans are under fire, that is not an order the Commander in Chief has to give twice. Our military does everything humanly possible to save American lives — and would do more if they could. That anyone has ever suggested otherwise is something I will never understand.”

The excerpt comes in advance of a briefing Friday of members of Democratic-leaning groups by Clinton’s team about how she addresses the attacks in the book, according to Politico.

Clinton has retained Tommy Vietor, who worked with Clinton in the Obama administration as a National Security Council spokesman, to assist with publicity and messaging surrounding the book release.

“I had the privilege of working with Secretary Clinton and her team as she traveled around the world working to restore and strengthen our alliances and advance critical administration priorities,” Vietor said. “I’m excited to help tell the story of that work when she releases her book.”

Clinton’s spokesman, Nick Merrill, declined to comment on the Benghazi chapter.

“Until the book is released, there’s nothing to say,” Merrill said. “And once it’s released, it will speak for itself.”

Republicans quickly attacked Clinton over her account of the Benghazi attacks. In a statement, Republican National Committee spokeswoman Kirsten Kukowski said she made “wrong choices” on foreign policy.

“Team Hillary leaked the Benghazi chapter from her book continuing the company line – blaming Republicans,” Kukowski said. “The White House and Democrats including Hillary Clinton have been less than forthcoming with information from the very beginning – emails prove Democrats coordinated to put the White House and politics before the facts – and Republicans are going to continue getting answers for the families of those lost but also the rest of America so it doesn’t happen again.”