Judge Jackson took questions for nearly 13 hours Tuesday before the Senate Judiciary Committee -- where Democrats hailed her for breaking barriers and Republicans attempted to brand her as "soft on crime” -- but Jackson refused to play into political fights and vowed repeatedly to “stay in my lane.”

In several tense exchanges with Republicans on the committee, Jackson defended her record as both a lawyer and a judge.

She called her service as a federal public defender -- including defense of accused terrorists held without charge at Guantanamo Bay -- an act of "standing up for the constitutional value of representation." Faced with allegations she was too lenient on child pornography offenders, Jackson stressed that she followed federal sentencing guidelines set by Congress and got emotional when talking about reviewing evidence in what she called “heinous” and "egrigous" crimes.

Jackson also resisted repeated attempts to classify her “judicial philosophy,” claiming she doesn’t have one, but she did lay out a "methodology" she’s developed for approaching each case: proceed from a position of neutrality, evaluate the facts, and apply the law to facts in the case.

Asked also about same-sex marriage, abortion, and the right to own a gun in the home, Jackson said the Supreme Court has established those rights and that she is bound to stare decisis as a jursist.

Read more key takeaways from Tuesday’s session here.

-ABC News’ Devin Dwyer

An unflappable Jackson endured over 12 hours of questioning on Tuesday.

Multiple senators pressed her on her decisions in sentencing defendants in child porn cases.

The judge also addressed crime, abortion, gender, critical race theory and her representation of Guantanamo Bay detainees.

Jackson's confirmation hearing will resume at 9 a.m. Wednesday to wrap up first-round questioning from two remaining senators: Jon Ossoff, D-Ga., and Thom Tillis, R-N.C. The hearing then moves on to the second round of questions.

Sen. Marsha Blackburn, R-Tenn., who is pro-life, brought up abortion, asking Jackson, "Can you explain to me, on a constitutional basis, the court's decision in Roe -- and where is abortion protected in the constitution?

Jackson acknowledged abortion isn't mentioned in the Constitution. But she stressed, "Abortion is a right that the Supreme Court has recognized is one of the kinds of rights that is unenumerated."

The Supreme Court is set to take up one of the largest threats to abortion protections guaranteed by Roe v. Wade and Planned Parenthood v. Casey with their consideration of Dobbs v. Jackson's Women's Health Organization, a challenge to a Mississippi law that bans nearly all abortions after 15 weeks of pregnancy.

Jackson told Blackburn, "Whatever the Supreme Court decides in Dobbs will be the precedent of the Supreme Court. It will be worthy of respect in the sense that it is the precedent and I commit to treating it as I would any other precedent."

Blackburn also asked the nominee about gender, first asking if she thinks "schools should teach children that they can choose their gender." Jackson declined to comment.

When Blackburn asked Jackson if she could define the word "woman," she replied, "Not in this context -- I'm not a biologist."

"In my work as a judge, what I do is I address disputes. If there is a dispute about a definition, people make arguments and I look at the law and I decide," Jackson said.

Blackburn also asked about transgender athletes, mentioning a collegiate transgender swimmer who recently won a women's 500-yard freestyle event. Blackburn said, "What message do you think this sends to girls who aspire to compete and win in sports at the highest levels?"

"I'm not sure what message that sends," Jackson said. "If you're asking me about the legal issues, those are topics that are being hotly discussed, as you say, and could come to the court."

-ABC News' Brittany Shepherd

In a light-hearted moment, when Sen. Alex Padilla, D-Calif., began his questioning, Jackson acknowledged it is his birthday.

Padilla's first question for Jackson was why she wants to join the Supreme Court.

She said, "I came to love the law starting as early as 4 years old watching my dad study when he went back to law school when I was a child."

"I would just be so honored to have the opportunity to use my time and talents in this way," she said.

Padilla asked about Jackson's clerkship experience and if she thinks there should be a more diverse pool of law clerks.

Jackson clerked for three federal judges, including Supreme Court Justice Stephen Breyer, whose seat she is nominated for.

As a clerk, she said, "I got to understand how judges think as they evaluate cases, which for a young lawyer is an extraordinary training opportunity."

"I know how important it is for people to see that people like me are in the judicial branch … it's been part of my practice to go to schools, to reach out to young people, to tell them about clerking, to try to get them to apply," she said. "I think it's to the benefit of us all to have as many different law students seeking clerkships as possible."