Sen. Patrick Leahy, D-Vt., gave Judge Jackson a chance to defend herself against GOP attacks that she's "soft on crime or even anti-law enforcement because you accepted your duties as a public defender," he said.

Jackson said criminal defense lawyers perform a service but stressed that people must be held accountable for a society to function.

"As someone who has had family members on patrol and in the line of fire, I care deeply about public safety I know what it is like to have loved ones who go off to protect and to serve and the fear of not knowing whether or not they'll come home again because of crime in the community," she said, noting her brother and two uncles' careers in law enforcement.

"The need for law enforcement, those are not abstract comments or political slogans to me. As a lawyer and citizen, I care deeply about our Constitution and the rights that make us free," she said.

Leahy also used his time to bring up former Republican House Speaker Paul Ryan's praise of Jackson. Jackson's brother-in-law is married to Ryan's sister-in-law.

"That's powerful praise. And I think it goes to a fundamental point -- one doesn't have to have the same political beliefs or ideology as a judicial nominee to recognize their integrity or intellect," Leahy said.

As she reintroduces herself to the American public as well as the Senate Judiciary Committee, Ranking Republican Sen. Chuck Grassley, R-Iowa, asked Jackson what aspect of her record as a judge does she believe has been the most important for the good of the country.

"Well, I think that all of my record is important to some degree because I think it clearly demonstrates that I'm an independent jurist, that I am ruling in every case consistent with the methodologies that I've described, that I'm impartial," Jackson said.

"I don't think anyone could look at my record and say that it is pointing in one direction or another or that it is supporting one viewpoint or another. I am doing the work and have done the work for the past 10 years that judges do to rule impartially and to stay within the boundaries of our proper judicial role," she added.

Trying to home in further on her judicial philosophy, Grassley asked, of the previous 115 justices, are there any of them now or in the past that has a judicial philosophy that most closely resembles her own. She said she hasn't studied the philosophies of all of the prior justices but that her background as a trial judge resembles that of left-leaning Justice Sonia Sotomayor.

"I will say that I come to this position, to this moment as a judge who comes from practice -- that I was a trial judge and my methodology has developed in this context. I don't know how many other justices other than Justice Sotomayor have that same background," she said.

Jackson has also emphasized in previous confirmations hearings that she does not have a judicial philosophy per se, but she applies the same methodology to all the cases she approaches, regardless of its parties.

-ABC News' Trish Turner

Ranking Member Sen. Chuck Grassley, R-Iowa, tried to get more clarity on whether Judge Jackson would support the idea of expanding the Supreme Court beyond nine justices, but Jackson said that was a policy question she couldn't answer.

The question comes after several Republicans said Monday they were disappointed that Jackson hasn't clarified her position on court-packing after she received the support of the progressive group Demand Justice, which is pushing for the court's expansion.

"Respectfully, senator, other nominees to the Supreme Court have responded as I will, which is that it is a policy question for Congress," Jackson said. "I am particularly mindful of not speaking to policy issues because I am so committed to staying in my lane of the system. Because I'm just not willing to speak to issues that are properly in the province of this body."

Presented with the fact that retiring Justice Stephen Breyer and the late Justice Ruth Bader Ginsburg stated their views on the position, Grassley then asked if the Supreme Court has been bought by dark money groups.

"Senator, I don't have any reason to believe that that's the case," she replied. "I have only the highest esteem for the members of the Supreme Court whom I hope to be able to join, if I'm confirmed, and for all of the members of the judiciary."

Continuing to give Judge Jackson opportunities to respond to GOP attacks, Senate Judiciary Chairman Dick Durbin, D-Ill., also asked her what impact representing Guantanamo Bay detainees had on her judicial career after Republicans made clear they will take aim at those cases she was assigned as a federal public defender.

"September 11th was a tragic attack on this country. We all lived through it," she began. "We saw what happened, and there were many defenses, important defenses that Americans undertook. There were Americans whose service came in the form of military action. My brother was one of those Americans, those brave Americans who decided to join the military to defend our country."

"After 9/11, there were also lawyers who recognized that our nation's values were under attack, that we couldn't let the terrorists win by changing who we were fundamentally," she continued. "And what that meant was that the people who were being accused by our government of having engaged in actions related to this, under our Constitutional scheme, were entitled to representation -- were entitled to be treated fairly. That's what makes our system the best in the world. That's what makes us exemplary."

She reminded the committee that federal public defenders don't get to pick their clients but said, "You are standing up for the constitutional value of representation -- and so I represented, as an appellate defender, some of those detainees."