Lawyer Victoria Toensing has another view. She said members of the House Permanent Select Committee on Intelligence displayed incompetence while questioning Mr. Morell.

“Nobody from the House committee asked about her,” said Mrs. Toensing, who represents Gregory Hicks, the chief of mission in Tripoli that day who was among the first to blow the whistle on lax security in Benghazi and a lack of help from Washington during the crisis. “Was that hearing somewhat incompetent? Yes.”

In the early post- Benghazi days on Capitol Hill, Republicans tried to pry “what did she know and when did she know it” information out of witnesses. But in later hearings, her name came up rarely — if at all.

On key questions, there is a dead end. For example, the nation’s two most senior military officials said they never spoke with Mrs. Clinton during the eight-hour crisis in Benghazi, Libya.

The State Department refused to cooperate for a Senate Select Committee on Intelligence investigation, Republicans say, and her name is not in the final report.