For the last several months, Tanden has been a senior adviser to the president, working quietly behind the scenes to build support among interest groups for his social spending agenda and overseeing a government reform agenda with officials at the budget office.

Tanden had previously served as the president of the Center for American Progress, a liberal think tank, and was a close adviser to former Sen. Hillary Clinton. In her new job, Tanden will be at the center of the flow of information between Biden and his senior White House advisers.

A White House official, who asked to remain anonymous because he was not authorized to speak publicly about internal staff moves, described Tanden’s new role as “the central nervous system of the White House,” helping to facilitate presidential decision-making.

But the official said that Tanden would retain the title of senior adviser and would continue to offer advice to the president and other senior White House officials on a range of topics.

The decision by Biden is a remarkable comeback for Tanden, who met fierce resistance from members of the Senate on both sides of the aisle for her frequent caustic remarks on social media.

During the four years of President Donald Trump’s administration, Tanden fashioned herself as a fierce and outspoken liberal critic of the administration and lawmakers — in both parties — who she felt were not adequately supportive of the causes she believed in.

On Twitter, she often expressed her views with unsparing language. Once she was nominated to lead the budget office, those comments proved challenging to explain away.

In 2017, when Sen. Lisa Murkowski of Alaska, a moderate Republican, announced she was supportive of Trump’s effort to lower the corporate tax rate, Tanden lashed out.

“No offense but this sounds like you’re high on your own supply,” she wrote on Twitter. “You know, we know, and everyone knows this is all garbage. Just stop.”

In February, a spokesman for Sen. Mitt Romney, R-Utah, said it would be “hard to return to comity and respect with a nominee who has issued a thousand mean tweets.”

The job of staff secretary is rarely a high profile one. But it is known inside the White House as a powerful position because of the access that the occupant has to information.

Top White House advisers who want the president to sign off on policy proposals will now have to send paperwork through Tanden. She will control the flow of that paperwork, deciding what documents get to the president’s desk and when they are delivered.

Some high-profile names in Washington have served as staff secretary. John Podesta, the founder of the Center for American Progress and a former chief of staff to former President Bill Clinton, was also staff secretary to Clinton. Brett Kavanaugh, who now is an associate justice on the Supreme Court, was staff secretary for former President George W. Bush.