Anita Dunn, a top adviser to President Biden and architect of his 2020 campaign, will leave the White House next week to advise the largest super PAC supporting Vice President Harris.

The decision, which has long been discussed as a possibility inside Biden’s inner circle, marks the first major exit from Biden’s core team since he decided to step aside from the presidential campaign and endorse Harris.

“She’s tough and tested, and her experience and intellect have helped us deliver historic results for the American people,” Biden said in a statement Tuesday about Dunn. “I deeply value her counsel and friendship and I will continue to rely on her partnership and insights as we finish the job over the next six months.”

Dunn will be a senior adviser to the independent group Future Forward, which has committed at least $300 million to support Harris, and an adviser to its partner organization Future Forward USA Action. Dunn will work on super PAC efforts that can coordinate with the Harris campaign, meaning she will not be able to consult on independent ad placement or message strategy, say people familiar with the arrangement.

“I am grateful to President Biden and Vice President Harris for their leadership and giving me the opportunity to be part of what they have accomplished for the American people,” Dunn said in a statement.

She helped structure the ecosystem of outside groups for Biden during 2021 and 2022, and worked closely with the groups last year, when legal restrictions on coordination were less strict. She does not plan to join a consulting firm, and would work as an independent consultant. Future Forward President Chauncey McLean said in a statement that the group was “thrilled” to have her rejoining the effort.

Dunn worked in the White House for Biden on two temporary assignments starting in January 2021, before divesting from her consulting firm SKDK in 2022 to work full time as a senior adviser to the president. She worked with the Center for American Progress on a project that developed the “ultra MAGA” communications strategy that Democrats, including Biden, adopted before the 2022 midterms.

Since then, she has overseen the White House communications operation, managed the policy rollouts and advised Biden’s 2024 campaign as it set up operations and began planning for next month’s convention in Chicago.

She was previously a part of the inner circle that advised Biden when he considered and decided against a presidential campaign in 2015. She then took on a central role in the 2020 campaign, serving briefly as an interim campaign manager after Biden’s fourth-place finish in the Iowa caucuses. Campaign aides credit her with the Nevada and South Carolina strategy that allowed Biden to win the nomination, despite embarrassing defeats earlier in the process.

Previously she served as a top adviser to Barack Obama’s 2008 and 2012 campaigns, including a brief stint as White House communications director during Obama’s first term. She advised former senator Bill Bradley (D-N.J.) when he ran for president in 2000 against Vice President Al Gore. She first worked in the White House for President Jimmy Carter in 1978, where she got to answer phones in the chief of staff office after cuts to the full-time staff.

Her husband, former White House counsel Bob Bauer, is Biden’s personal attorney.

“The President and the entire team turn to Anita for her always insightful counsel, decisiveness, and unparalleled experience every single day,” White House chief of staff Jeff Zients said in a statement Tuesday. Harris’s chief of staff, Lorraine Voles, praised Dunn as “a valued colleague to me and so many others,” while White House Deputy Chief of Staff Bruce Reed called her “a clutch hitter.” Minyon Moore, chair of the Democratic convention, described Dunn as “the person who can get things done and get you answers.”

News of her departure led to an outpouring of other tributes from those who have worked with her or been mentored by her over the past decade, including White House spokesman Andrew Bates, who called her “unfailingly supportive.” Dozens of Democratic operatives credit Dunn with jump-starting and guiding their careers.

“She’s been a great mentor to me and scores of communicators across the administration,” White House communications director Ben LaBolt said in a statement.

At the White House, her chief of staff, Jordan Finkelstein, created an email distribution list, called WWBakedGoodAlert, to inform staff when Dunn brought in freshly baked goods to share. She baked blackberry lemon cake Tuesday morning, said one person familiar with her cooking schedule, who spoke on the condition of anonymity because they were not authorized to speak publicly.

“She is so confident and fearless in what she does,” said T.J. Ducklo, a communications adviser to the Harris campaign, who worked for Dunn in the Biden White House and on his 2020 campaign. “When she gives you an assignment and says, ‘You are going to do this, and I know you can,’ it makes you feel like you can.”