Susan Rice ’86, U.S. ambassador to the United Nations, has withdrawn her name from consideration for secretary of state in a letter to President Barack Obama.

Rice, who has advised the president since he first ran for the office in 2008, had been a front-runner for the position currently held by Hillary Clinton.

“I am highly honored to be considered by you for appointment as secretary of state. … However, if nominated, I am now convinced that the confirmation process would be lengthy, disruptive and costly. … That trade-off is simple not worth it to our country,” she wrote in her Dec. 13 letter to the president.

Rice has come under fire recently for comments she made about the Sept. 11 Benghazi terrorist attack, in which four Americans were killed, including Chris Stevens, the U.S. ambassador to Libya.

On Sept. 16, five days after the attack, Rice went on a circuit of Sunday news shows to report that the attack was a spontaneous event precipitated by an amateur, anti-Muslim video.

“[Our] current best assessment, based on the information we have at present, is that, in fact, what this began as was a spontaneous — not a premeditated — response to … a violent protest that was undertaken in reaction to this very offensive video that was disseminated,” she said on ABC’s “This Week.”

The White House has since confirmed the attack was an act of terrorism.

In the early days of her consideration, Republicans were already questioning her judgment in the Benghazi attack and her fitness to serve as secretary of state.

“I will do everything in my power to block [Rice] from being the United States secretary of state,” Senator John McCain said on “Fox and Friends.” “She has proven that she either doesn’t understand or is not willing to accept evidence on its face.”

President Obama, when asked about Rice’s critics, offered a vigorous defense of his U.N. ambassador.

“If Senator McCain … want[s] to go after somebody, [he] should go after me,” Obama said. “[Rice] has represented the United States and our interests in the United Nations with skill and professionalism and toughness and grace.”

Had she been confirmed, Rice would have joined Condoleezza Rice to become the second Stanford-affiliated African-American woman to serve in the position.

Susan Rice’s Stanford education found its way to the floor of the U.N. Security Council in December 2011, during an argument with Russian Ambassador to the United Nations Vitaly Churkin. Churkin urged U.N. investigations into NATO conduct in Libya, to which Rice responded, “Let us see this for what it is: It is duplicitous, it’s redundant, it’s superfluous and it’s a stunt.”

Churkin responded in a press briefing the next day, as reported by Foreign Policy.

“This is not an issue that can be drowned out by expletives. You might recall the words one could hear: bombast and bogus claims, cheap stunt, duplicitous, redundant, superfluous, stunt,” he said. “Oh, you know, you cannot beat a Stanford education, can you?”

“We hear that the Obama administration wants to establish a dialogue with the international community in the United Nations, “ he added. “If that is to be the case … really this Stanford dictionary of expletives must be replaced by something more Victorian.”

President Obama accepted Rice’s withdrawal from the secretary of state nomination consideration process. In a statement released by the White House he said, “The American people can be proud to have a public servant of her caliber and character representing our country.”

Rice will remain in her positions as U.S. permanent representative to the United Nations and member of President Obama’s cabinet and National Security Council.