UN Ambassador Susan Rice has an op-ed in the Washington Post explaining her decision.
On Thursday I asked that President Obama no longer consider me for the job of secretary of state. I made this decision because it is the right step for this country I love. I have never shied away from a fight for a cause I believe in. But, as it became clear that my potential nomination would spark an enduring partisan battle, I concluded that it would be wrong to allow this debate to continue distracting from urgent national priorities — creating jobs, growing our economy, addressing our deficit, reforming our immigration system and protecting our national security.
These are the issues that deserve our focus, not a controversy about me.
Rice also addressed the controversy surrounding her media appearances following the Benghazi tragedy.
When discussing Benghazi, I relied on fully cleared, unclassified points provided by the intelligence community, which encapsulated their best current assessment. These unclassified points were consistent with the classified assessments I received as a senior policymaker. It would have been irresponsible for me to substitute any personal judgment for our government’s and wrong to reveal classified material. I made clear in each interview that the information I was providing was preliminary and that ongoing investigations would give us definitive answers.