Susan Rice, the embattled US ambassador to the United Nations, withdrew herself from consideration to replace Hillary Clinton as secretary of state in the face of sustained Republican attacks over her handling of the Benghazi consulate attack.
Although Rice insisted the decision had been hers alone and that she was not pushed by the Obama administration, it provides the Republicans with an early victory barely a month after the presidential election.
The danger for Barack Obama, even though the White House insists it did not push her, is that it will be interpreted as weakness by a president reluctant to face a fractious nomination battle.
Her withdrawal means that John Kerry, Massachusetts senator and former presidential candidate, is almost certain to be nominated to be America's top diplomat.
Rice wrote to Obama asking him to no longer consider her for the job because, she said, she would face "a lengthy, disruptive and costly" nomination battle with the Senate.
"The position of secretary of state should never be politicised," Rice wrote. "As someone who grew up in an era of comparative bipartisanship … I am saddened that we have reached this point, even before you have decided whom to nominate. We cannot afford such an irresponsible distraction from the most pressing issues facing the American people."
In a statement released by the White House, Obama expressed regret and described the attacks as "unfair and misleading".
She is to stay in her position as UN ambassador, Obama said.
The president is in the process of putting together his cabinet for a second term after many of the present team expressed a desire to leave. It emerged on Thursday that Obama is lining up a former Republican senator, Chuck Hagel, to replace Leon Panetta as defence secretary, an effort to present his administration as being broad-based.
Normally by this stage a president would have announced some appointments, but Obama's plans have been disrupted by the consistent Republican sniping against Rice, led by senators John McCain, Lindsey Graham and, lately, Kelly Ayotte.
"Senator McCain thanks ambassador Rice for her service to the country and wishes her well," said McCain's spokesman Brian Rogers. "He will continue to seek all the facts surrounding the attack on our consulate in Benghazi that killed four brave Americans."
Graham, in a statement, said: "I respect ambassador Rice's decision. President Obama has many talented people to choose from to serve as our next secretary of state."
Her withdrawal, revealed by NBC News, appears to be on mainly personal grounds, with the attacks expanding beyond just her comments on Benghazi to prying into her private life, including such things as her investments.
In an interview with NBC's Brian Williams, broadcast on Thursday night, Rice said she took the decision to avoid distracting from the main priorities Obama's second term.
"We're talking about comprehensive immigration reform, balanced deficit reduction, job creation, that's what matters, and to the extent that my nomination could have delayed or distracted or deflected or maybe even some of these priorities impossible to achieve, I didn't want that and I'd much prefer to continue doing what I'm doing, which is a job I love at the United Nations."
Her insistence that she volunteered to step aside was given credence by Bill Burton, a former White House spokesman and now a strategic adviser at the main Democratic political action committee, Priorities USA. In a tweet, he wrote: "You don't see a lot of people take one for the team in Washington - what ambassador Rice did was selfless and truly extraordinary."
Rice is a big prize for the Republicans. She was championed by both Michelle Obama and senior White House adviser Valerie Jarrett, in spite of having a reputation for being abrasive.
It was that combative, highly political approach that first got her into trouble with McCain when, during the 2008 presidential election, she mocked him for wearing a flak-jacket on a visit to Baghdad at a time when he was surrounded by dozens of security staff and soldiers. McCain, a Vietnam veteran, took the criticism badly.
The assault on Rice followed a series of television interviews she gave on Sunday talk shows after the attack on Benghazi that left four Americans, including the ambassador Chris Stevens, dead. Rice suggested that the attack had been launched by demonstrators upset about anti-Muslim video made in the US. She later acknowledged she had been wrong and that the attack had been mounted by an al-Qaida-linked group.
Attempts last month in Washington to win over critical senators failed, enraging them further.
In her letter, she told Obama: "If nominated, I am now convinced that the confirmation process would be lengthy, disruptive and costly – to you and to our most pressing national and international priorities.
"That trade-off is simply not worth it to our country … Therefore, I respectfully request that you no longer consider my candidacy at this time."
Obama, in his statement, said: "For two decades, Susan has proven to be an extraordinarily capable, patriotic, and passionate public servant … I am grateful that Susan will continue to serve as our ambassador at the United Nations and a key member of my cabinet and national security team, carrying her work forward on all of these and other issues."
Kerry is well-placed to sail through the nominating process. The Senate foreign relations committee is responsible for screening the secretary of state and Kerry, as head of it, knows well all the members.
McCain has applied to join the committee from January and could have used that position to throw up obstacle after obstacle for Rice. But he is on relatively good terms with Kerry.
Kerry, in a statement, said of Rice: "As someone who has weathered my share of political attacks and understands on a personal level just how difficult politics can be, I've felt for her throughout these last difficult weeks, but I also know that she will continue to serve with great passion and distinction."
guardian.co.uk © Guardian News and Media Limited 2010