GOWDY ON THE DEFENSIVE

Gowdy, a former federal prosecutor, has been on the defensive over a series of comments from his fellow Republicans implying the committee's real aim was to deflate Clinton's poll numbers.

"Madame Secretary, I understand some people - frankly in both parties - have suggested this investigation is about you. Let me assure you it is not," Gowdy told Clinton. "Not a single member of this committee signed up for an investigation into you or your email system."

Clinton refrained from questioning the panel's motives, which she has done in recent public statements on the campaign trail.

"Despite all the previous investigations and all the talk about partisan agendas, I'm here to honor those we lost and to do what I can to aid those who serve us still," she said.

She said the emails being made public and examined by the committee did not encompass all of the work she did as secretary of state.

"I don't want you to have a mistaken impression about what I did and how I did it," she said. "Most of my work was not done on emails with my closest aides, with officials in the State Department, officials in the rest of the government."

She cited communications through secure phone calls, in-person conversations and top-secret documents.

The committee's Democrats, who may discuss abandoning the inquiry after Clinton's appearance, say they think there is little left to unearth on Benghazi.

A 2012 report by a government accountability review board sharply faulted State Department officials for providing "grossly" insufficient security in Benghazi, despite upgrade requests from Stevens and others in Libya.