The four-day confirmation hearing for Judge Barrett is underway in the Senate Judiciary Committee.

Republicans are expected to push for a vote before Election Day as Democrats will try to stop her from turning the court sharply conservative for decades to come.

Committee chairman Sen. Lindsey Graham, R-S.C., is giving his opening statement first, to be followed by Ranking Member Sen. Diane Feinstein, D-Calif. Both appeared in-person and wore masks into the room.

Senators will follow with 10-minute opening statements before Judge Barrett is then introduced, sworn in and gives her opening statement.

Members were given the option of appearing and questioning the witness in person or remotely due to the coronavirus pandemic. Each senator makes their own determination.

The Capitol Hill press pool reported Barrett’s children, in attendance with her Monday, were running down the Capitol Hill hallways and into the hearing room with Barrett, who was wearing a black mask as she took her seat in the committee room.

ABC News’ Trish Turner

Judge Amy Coney Barrett has arrived to testify before the Senate Judiciary Committee on the first day of her Supreme Court confirmation hearing.

The hearings are expected to last a few days as Barrett will face questions from both Republican and Democratic senators on the committee.

The U.S. Supreme Court begins a new term on Monday amidst a raging political battle over an open seat and a high-stakes push by President Donald Trump to have the justices adjudicate a possible contested election.

"Lurking in the background is the possibility this could become the most tumultuous and divisive term since the Supreme Court decided Bush v. Gore 20 years ago," said Irving Gornstein, executive director of the Supreme Court Institute at Georgetown University.

The court will convene as a panel of eight for the first time since the death of Justice Ruth Bader Ginsburg as they await confirmation of Trump nominee Amy Coney Barrett, hearing oral arguments via teleconference that will be livestreamed to the public because of the coronavirus pandemic.

The justices face a fall docket of cases with implications for millions of American families and some of the nation's biggest businesses. They'll address matters of health insurance, use of force by police, military rape claims, religious freedom, grand jury secrecy, robocalls and faith-based foster care.

At the top of the list is a challenge to the Affordable Care Act brought by Texas and 18 Republican-led states backed by the Trump administration to completely invalidate the law, including protections for people with preexisting conditions. It will be argued Nov. 10 and decided by the end of June 2021.

"The stakes of this case have become only higher amidst the global pandemic. One estimate suggests there are 20 million people taking advantage of the exchanges," said University of Chicago law professor Jennifer Nou.

More on other key questions the court will consider this term can be found here.

-ABC News' Devin Dwyer

Democratic nominee Joe Biden and running mate Sen. Kamala Harris have faced growing pressure from Republicans to say whether they'd try to 'pack' the Supreme Court if Democrats were to win the White House and control of Congress in November, after both candidates have repeatedly dodged questions on the issue.

"You will know my opinion on court-packing when the election is over," Biden has said. "The moment I answer that question, the headline in every one of your papers will be about that rather than focussing on what's happening now. This election has begun. There's never been a court appointment once the election has begun."

The idea of adding more justices -- or what critics call "packing" the court to secure a desired majority -- is not unprecedented but has taken on new life with the death of Justice Ruth Bader Ginsburg and the Senate confirmation hearing for Judge Amy Coney Barrett.

Some Democrats -- including Senate Minority Leader Chuck Schumer -- and progressive groups have threatened to try to add justices to counter the effort by President Donald Trump and Senate Republicans to get Barrett confirmed before Election Day.

So, can a party in power really "pack" the court?

-ABC News' Devin Dwyer

Judge Barrett, who has been diligent in keeping her mask on throughout the hearing, except for an occasional sip of water, removed it to be sworn in and to deliver her opening statement.

“As I said when I was nominated to serve as a justice, I am used to being in a group of nine -- my family," Barrett began. "Nothing is more important to me, and I am so proud to have them behind me."

Barrett said she'd bring new perspectives to the bench as she'd be the first mother of school-age children to serve, the first justice from the Seventh Circuit in 45 years and the only sitting justice who didn’t attend Harvard or Yale law schools.

After speaking of her own upbringing and family of nine, Barrett turned to how she interprets the law, following in the textualist and originalist approach of Justice Antonin Scalia, for whom she clerked. "It was the content of Justice Scalia's reasoning that shaped me. His judicial philosophy was straightforward: 'A judge must apply the law as it is written, not as she wishes it were,'" she said.

“Justice Scalia taught me more than just law. He was devoted to his family, resolute in his beliefs, and fearless of criticism. And as I embarked on my own legal career, I resolved to maintain that same perspective,” she said. “I worked hard as a lawyer and a professor; I owed that to my clients, my students, and myself. But I never let the law define my identity or crowd out the rest of my life.”

Barrett said a similar principle of separation applies to the role of the courts, a line that will likely pick up traction in questioning from Democrats.

“The policy decisions and value judgments of government must be made by the political branches elected by and accountable to the people. The public should not expect courts to do so, and courts should not try,” she said.

Invoking her children, Barrett described the standards she says she sets for herself on ruling in any court, another line Democrats will likely seize on in their arguments for upholding the Affordable Care Act.

“When I write an opinion resolving a case, I read every word from the perspective of the losing party. I ask myself how would I view the decision if one of my children was the party I was ruling against: Even though I would not like the result, would I understand that the decision was fairly reasoned and grounded in the law?” she said.

Barrett said she never sought out the Supreme Court nomination and thought carefully before accepting, acknowledging she will never take the place of Justice Ginsburg.

“I have been nominated to fill Justice Ginsburg’s seat, but no one will ever take her place. I will be forever grateful for the path she marked and the life she led,” she said.