SAN FRANCISCO — Donna Brazile, who has spent most of her life running Democratic campaigns and working within the party machinery, on Thursday night painted a deeply pessimistic portrait of the party.

The former interim chair of the Democratic National Committee said Democrats couldn’t win back power from the Trump administration unless the party’s old guard lets a new generation of leaders take the reins.

“I don’t want the Dianne Feinsteins and the Nancy Pelosis of the world to leave the room. I want them to just scoot over, make room,” she said at a talk hosted by the Commonwealth Club at the Marines’ Memorial Theatre.

Brazile spoke just days after her new tell-all book sent shockwaves through national Democratic circles with its unvarnished criticism of Hillary Clinton’s 2016 campaign for president.

In “Hacks: The Inside Story of the Break-ins and Breakdowns That Put Donald Trump in the White House,” Brazile reveals that she considered replacing Clinton as the Democratic nominee with then-Vice President Joe Biden in September 2016 after Clinton collapsed at a 9/11 ceremony in New York City.

Brazile strongly implies in the book that she believed the 2016 primary was “rigged” against Vermont Sen. Bernie Sanders. She wrote that she promised Sanders she would find proof of “whether or not Hillary’s team had rigged the party process in her favor so that only she could win the nomination.” When she finished that investigation, “I had found my proof and what I had found broke my heart,” Brazile wrote.

President Donald Trump and conservative commentators have seized on those comments, with Trump tweeting last week that Brazile’s account proves that the primary was “bought and paid for by Crooked H.”

But on Thursday night — and in other interviews since the excerpts of her book were published last week — Brazile seemed to walk her claims back.

“I found no evidence that the quote-unquote primary was rigged,” Brazile said, explaining that she instead found evidence that the Clinton campaign was in control of certain parts of the DNC before Clinton won the primary. “I was worried that this would give the impression that the DNC was in the tank for one candidate, and that, in my judgment, was immoral,” she said.

Meanwhile, Clinton and her allies have pushed back hard against Brazile’s description of events. “That just wasn’t the case,” Clinton said of Brazile’s claims about party financing in an interview with NBC late-night host Seth Meyers on Wednesday.

Brazile, a longtime party strategist, was thrust into the DNC leadership position in July 2016 amid party turmoil and leaked emails showing committee staffers mocking Sanders and his campaign. She had previously managed Al Gore’s 2000 presidential campaign and worked on other races around the country.

While most of America saw Clinton as the overwhelming favorite throughout 2016, Brazile described a campaign that was flailing behind closed doors. She said her concerns about a lack of resources for party activists on the ground in swing states like Michigan and Wisconsin were shrugged off at Clinton’s Brooklyn headquarters.

“It was so condescending that I used to scream,” she said.

One suggestion she had for Clinton: “She should have asked Bill to go hang out in Detroit, bring your saxophone,” Brazile joked. “That man can play some tenor sax.”

Brazile also focused her hour-and-a-half talk on the Russian hackers who bedeviled the DNC and team Clinton and, she warned, could strike again in the 2018 elections. She first found out about the hack while “grooving” at a Beyoncé concert, she recounted.

For a consummate Democratic insider, Brazile sounded surprisingly downbeat on the American two-party system.

“They’re becoming less and less relevant,” she said of the Democratic and Republican parties. “They have become ATMs now for special interests, and I am bothered by that.”

At the same time, she heralded the Democratic victories in elections on Tuesday in Virginia, New Jersey and other states, which she said were the result of grass-roots activism.

“We have to keep that up, that momentum, that bottom-up activity,” Brazile said.