Representative Elijah E. Cummings, the ranking Democrat on the Benghazi committee, offered a full-throated defense of Hillary Rodham Clinton’s honor, apologizing to her for his colleagues who suggested that she did not care for the people who died on her watch.

“I don’t know what we want from you,” Mr. Cummings said, accusing Republicans of using taxpayer dollars to try to destroy Mrs. Clinton’s presidential campaign. “Do we want to badger you over and over again until you do get so tired so we get the gotcha moment?”

Clearly touched by his words, Mrs. Clinton thanked Mr. Cummings and said that she had done all that she could to answer more than ten hours of questions. She then expressed hope that, somehow, statesmanship could overcome partisanship.

“It is deeply unfortunate that something as serious as what happened in Benghazi could ever be used for partisan political purposes,” she said. “I’m hoping that we can move forward together.”

— Alan Rappeport

Republican committee members spent much of Thursday’s hearing asking questions suggesting Hillary Rodham Clinton made mistakes leading up to the Benghazi attacks.

In the final hours of questioning, Representative Lynn Westmoreland, Republican of Georgia, put it to her more directly.

“You said you wondered what things you could have done differently,” Mr. Westmoreland said. “What were they?”

Mrs. Clinton explained that she wished there were a more reliable force of armed contractors at the compound and more help from the Central Intelligence Agency on the ground.

Unsatisfied that she was dodging the question, Mr. Westmoreland said, “I’m trying to be nice.”

Mrs. Clinton went on to say that she was not sure that anything could have been done to stop the attackers considering the way the attack played out. As for her own responsibility, Mrs. Clinton said she was involved with recommending Ambassador J. Christopher Stevens for the job and working on Libya policy before and after the fall of the regime.

“I was responsible for quite a bit, Congressman,” she said. “I was not responsible for specific security requests.”

— Alan Rappeport

Representative Peter Roskam, Republican of Illinois, accused Hillary Rodham Clinton of using Libya as an opportunity to burnish her credentials as secretary of state and establish a “Clinton Doctrine.”

In a fiery exchange, Mr. Roskam read a series of emails between Mrs. Clinton and her staff members that he said showed how they were trying to shape the narrative surrounding America’s Libya policy and present Mrs. Clinton in a positive light.

“You were thinking about credit for you, isn’t that right?” said Mr. Roskam, before reading a message from her confidant, Sidney Blumenthal, in which he said that she needed to become the public face of Libya’s political transition.

Mrs. Clinton said that she was proud of the role she had, but that ultimately President Obama made the final decision on Libya. She said it was not unusual for someone in her position to explain foreign policy to the public.

Mr. Roskam disagreed, saying that Mrs. Clinton was being self-serving.

“Let me tell you what I think the Clinton Doctrine is,” he said. “I think it’s where an opportunity is seized to turn progress in Libya into a political win for Hillary Rodham Clinton.”

— Alan Rappeport

Representative Trey Gowdy pushed back at the insinuation from Representative Adam Schiff that the Benghazi committee had already reached its conclusions about what responsibility Hillary Rodham Clinton had for the 2012 attack.

“There is no theory of the prosecution, Mr. Schiff, because there is no prosecution,” Mr. Gowdy said. “This is an investigation.”

Mr. Gowdy advised his Democratic colleague not to reach any conclusions until the end of that investigation, and reminded him that there are 20 more witnesses who need to be questioned.

In the first demonstration of political theater, Representative Susan W. Brooks, Republican of Indiana, presented Mrs. Clinton with two giant stacks of her emails as she launched into a round of questions about her attention to the situation in Benghazi.

One pile, from 2011, had nearly 800 emails. The other, from the following year, had 67. Mrs. Brooks suggested that the difference represented a lack of interest in what was happening there at the time Ambassador Stevens was killed.

Mrs. Clinton responded by saying the job of secretary of state was not conducted entirely by email.

“I did not do the vast majority of my work by email,” she said, explaining that she had private meetings and secure phone calls with aides. “I don’t want you to have a mistaken impression about what I did and how I did it.”

— Alan Rappeport

Hillary Rodham Clinton said in her opening statements that any questioning about the attacks in Benghazi should strive to dignify the memories of the Americans who died there, and she argued that the United States should not retreat from a volatile and violent world.

After sharing some memories of Ambassador J. Christopher Stevens, who was killed in the attacks, Mrs. Clinton reminded the committee that she had already taken responsibility for what happened. She said she had tried to put reforms in place to keep diplomats safer.

Mrs. Clinton said that diplomats would always face risks abroad and that there would never be perfect security. She also recalled previous attacks on American diplomats in Lebanon and in Africa, noting that Republicans and Democrats managed bipartisan responses to those incidents.

“I’m here to honor those we lost,” Mrs. Clinton said, after listing the several investigations and inquiries into the incident. “My challenge to you, members of this committee, is the same challenge I put to myself. Let’s be worthy of the trust the American people have bestowed upon us.”