(JTA) — Hillary Clinton blamed attacks against her by Bernie Sanders during the Democratic primary for president on her eventual loss in the general election to Donald Trump.

In excerpts from Clinton’s forthcoming book What Happened, the former secretary of state wrote that the attacks by Sanders, a Vermont senator, caused “lasting damage” and were instrumental in “paving the way for Trump’s Crooked Hillary campaign.”

The book is scheduled to be released on Sept. 12, but Clinton supporters have posted photos of pages from the book on social media.

Clinton also said that she appreciated that Sanders campaigned for her in the general election.

“But he isn’t a Democrat – that’s not a smear, that’s what he says,” she wrote of the Independent. “He didn’t get into the race to make sure a Democrat won the White House, he got in to disrupt the Democratic Party.”

Clinton praised Sanders, a long shot for the nomination, for engaging “a lot of young people in the political process for the first time, which is extremely important.”

Clinton also wrote that President Barack Obama counseled her to “grit my teeth and lay off Bernie as much as I could,” according to the excerpts. She said that following that advice made her feel she was “in a straitjacket.”

Sanders, who will turn 76 this week, has not said whether or not he will run in the 2020 race, but did say in July that “I am not taking it off the table.”

CAP: Hillary Clinton and Bernie Sanders at the CNN Presidential Debate at the Brooklyn Navy Yard in New York, April 14, 2016. (Jewel Samad/AFP/Getty Images)