But such earnest attempts to lower the political temperature have so far failed. As so often in Washington, the clashes over Benghazi have a semi-hidden personal element that adds to the emotion. Senator John McCain, the Arizona Republican who led the initial lambasting of Ms. Rice, had been subjected to withering criticism by her in 2008 when he was running for president. And senators considering Ms. Rice’s future are quite aware that her main rival for the job of secretary of state is their colleague Senator John Kerry, Democrat of Massachusetts.

For now, the focus of Congress and the news media is mostly on language. For weeks after the Benghazi attack, Republicans accused Mr. Obama and his aides of avoiding labeling it “terrorism” for fear of tarnishing his national security record in the weeks before the Nov. 6 election. Since his re-election, that issue has faded, and the debate has shifted to the talking points.

The facts about the talking points, like those about the Benghazi attack itself, have dribbled out slowly and awkwardly from intelligence officials who generally do not relish airing their internal deliberations. But there is now a fairly clear account.

The C.I.A. and other intelligence agencies rarely prepare unclassified talking points; more often, policy makers submit proposed public comments, and intelligence analysts check them for classified information or errors of fact. But in the storm of news media coverage after the killings in Benghazi, C.I.A. officials responded quickly to Mr. Ruppersberger’s request on Sept. 14.

C.I.A. analysts drafted four sentences describing “demonstrations” in Benghazi that were “spontaneously inspired” by protests in Cairo against a crude video lampooning the Prophet Muhammad. (Later assessments concluded there were no demonstrations.) The initial version of the talking points identified the suspected attackers — a local militant group called Ansar al-Shariah, with possible links to Al Qaeda in the Islamic Maghreb, an offshoot of the terrorist network in North Africa.

But during a subsequent review by several intelligence agencies, C.I.A. officials were concerned that such specific language might tip off the malefactors, skew intelligence collection in Libya and interfere with the criminal investigation. So they replaced the names with the blanket term “extremists.”

Image Michael Morell, acting director of the C.I.A. Credit... J. Scott Applewhite/Associated Press

Ms. Rice has been skewered by Republican senators for her comments on Sunday television news programs on Sept. 16, which they have suggested were part of an administration cover-up of the terrorist nature of the attack and links to Al Qaeda. The criticism has barely been affected by the revelation that she accurately recited the talking points the intelligence agencies prepared.