Rice had recently been the subject of constant criticism from Republican pundits and lawmakers, with Sens. John McCain (R-AZ), Lindsey Graham (R-SC), and Kelly Ayotte (R-NH) leading the charge against her nomination.
At the center of the conflict was an appearance by Rice on NBC's Meet The Press on Sept. 16 in which she said U.S. intelligence suggested a deadly attack on the American consulate in Benghazi, Libya was caused by protests over an anti-Muslim film and that those protests had been hijacked by extremists. The attack was later determined to be an organized assault unrelated to protests in the Muslim world over the video.
Rice said in November that she "relied solely and squarely on the information provided to me by the intelligence community" in delivering her assessment. Intelligence officials said that they approved her talking points, having decided ties to organized terrorism, and specifically al Qaeda, were still unclear at that point just five days removed from the attack.
But conservative critics suggested nefarious motives behind her Meet The Press appearance and the story became a constant fixture on Fox News. McCain said the White House's response to Benghazi was "the worst cover-up or incompetence I have ever observed in my life" and compared it to the Watergate break-in that led President Nixon to resign. Republicans suggested that the White House had censored officials as part of a conspiracy to minimize the strength of al Qaeda. No evidence of such a plot has emerged.
Based on these concerns, McCain and his allies threatened to scuttle her nomination should she be tapped as Secretary of State. Seeking to cool things down, Rice met with her critics to address their concerns. But the Senators emerged only more determined to stop her from succeeding Hillary Clinton at the State Department.
Obama stood by Rice throughout, defending her from what he termed "outrageous" criticism at his first post-election press conference in November.
"If Sen. McCain and Sen. Graham want to go after somebody, they should go after me," Obama said at the time. "I'm happy to have that discussion with them. But for them to go after the U.N. Ambassador, who had nothing to do with Benghazi, and was simply making a presentation based on intelligence that she had received, and to besmirch her reputation is outrageous."
On Thursday, Obama responded to Rice's request with a similar statement.
"While I deeply regret the unfair and misleading attacks on Susan Rice in recent weeks, her decision demonstrates the strength of her character, and an admirable commitment to rise above the politics of the moment to put our national interests first," he wrote, adding that he would continue to rely on her as an "adviser and friend" regardless of her position in the next administration.
Senator Graham said in a statement that he respected Rice's decision, but "will continue working diligently to get to the bottom of what happened in Benghazi." A spokesman for McCain told CNN on Thursday that the senator "thanks Ambassador Rice for her service to the country and wishes her well," but will also continue his investigation of the administration's response to the attack.