Republicans continued to question Barrett on her impartiality, with Sen. Ben Sasse of Nebraska asking Barrett to confirm that judges can make decisions without imposing their own views.

"I hope that's what people think because that's what I have always driven to do. In my time as a judge, my job, my boss is the rule of law, not imposing my policy preferences," Barrett said.

Barrett was then asked to explain why judges wear black robes in our judicial system, in another opportunity to emphasize her commitment to the law, not her personal views in a courtroom.

"Chief Justice John Marshall started the practice in the beginning. Justices used to wear colorful robes that identified them with the schools they graduated from. John Marshall decided to wear a simple black robe. Pretty soon the other justices followed suit and now all judges do it," Barrett said, before offering her take on the garb.

“I think the black robe shows that justice is blind. We all dress the same. It shows once we put it on, we are standing united symbolically, speaking in the name of the law, not speaking for ourselves as individuals," she said.

Demonstrators protested the Senate Judiciary Committee hearing outside the Supreme Court Tuesday. One group wore masks and waved signs that featured Justice Ruth Bader Ginsburg's "dissenting collar."

Outside the Senate office building where Barrett's confirmation hearing was taking place, some of her supporters were praying.

Under questioning from Sen. Klobuchar, Barrett said Roe v. Wade is not a "super-precedent" -- so it could theoretically be overturned by the Supreme Court.

Earlier, Barrett said that Brown v. Board of Education, which established that racial segregation in schools is unconstitutional, is one of just a handful of cases she and some others consider to be "super-precedent" or settled law.

“Is Roe a super-precedent?” Klobuchar asked, before Barrett asked in return, “How would you define ‘super-precedent?’”

“I'm asking you,” Klobuchar said.

“People use super-precedent differently. The way that I was using it in the article that you’re reading was to define cases that are so well-settled that no political actors ... seriously push for their overruling. I'm answering a lot of questions about Roe v. Wade which I think indicates Roe v. Wade doesn't fall in that category. Descriptively means it's a case, not a case that everyone has accepted,” Barrett said.

Sen. Amy Klobuchar, D-Minn., used the metaphor of "following the tracks" to suggest how Barrett would likely vote on landmark cases involving health care, abortion and voting rights, using Barrett’s past writings and the words of President Trump.

"I think the American people have to understand that you would be the polar opposite of Justice Ginsburg," Klobuchar said. "She and Justice Scalia were friends, yes, but she never embraced his legal philosophy. So that's what concerns me."

Klobuchar pressed Barrett on voting rights, raising Barrett’s dissent in the Kanter v. Barr case Sen. Durbin raised earlier, in which Barrett suggested the Constitution protects the right of non-violent felons to own guns but does not protect their right to vote -- a right she wrote belongs "only to virtuous citizens."

"How do you define the word virtuous?" Klobuchar questioned. "It doesn't appear in the Constitution… We are living in a time or a lot of people are having their voting rights taken away from them. What's virtuous?

"Senator, I want to be clear that that is not in the opinion designed to denigrate the right to vote which is fundamental. The distinction between civic and individual rights is one that is present in the court decisions and it has to do with the jurisprudential view," Barrett said, saying it was a common, long-standing judicial term of art, not a character judgment. "It doesn't mean, I think, anybody gets a measure of virtue and whether they are good or not and whether they are allowed to vote. That's not what I said."

Barrett dodged several questions on election-related questions, citing the "Ginsburg rule."

"Do you think a reasonable person would feel intimidated by the presence of armed civilian groups at the polls?" she asked.

"Senator Klobuchar, you know that is eliciting. I'm not sure it's eliciting a legal opinion for me because a reasonable person standard, as you know, is more common in the law. Or just an opinion as a citizen. It's not something really that's appropriate for me to comment on," Barrett replied.

Sen. Chris Coons, D-Del., noting what President Trump has said about needing nine justices on the Supreme Court by the November election to decide any election-related disputes, asked Barrett if she will commit to recusing herself from those cases.

"Given what President Trump said, given the rest of the context of this confirmation, will you commit to recusing yourself from any case arising from a dispute in the presidential election results three weeks from now?" Coons asked.

"Thank you for giving me the opportunity to clarify this," Barrett began. "And I want to be very clear for the record and to all members of this committee that no matter what anyone else may think or expect, I have not committed or signaled, never even written -- I've had a couple of opinions that have been around this law, but I haven't even written anything that I would think anybody could reasonably say  this is how she might resolve an election dispute."

"I would consider it, and I certainly hope that all members of the committee have more confidence in my integrity then to think that I would allow myself to be used as a pawn to decide this election for the American people," Barrett continued.

"That would be on the question of actual bias, and you asked about the appearance of bias and you're right that the statute does require a justice or judge to recuse if there is an appearance of bias. And what I will commit to every member of this committee, to the rest of the Senate and to the American people is that I will consider all factors that are relevant to that question that requires recusal when there's an appearance of bias," she said.

Barrett went on to say she would discuss that with the other justices were a dispute to arise.

"Justice Ginsburg said it is always done with consultation of the other justices. So, I promise you that if I were confirmed and if an election dispute arises, both of which are if, that I would very seriously undertake that process and consider every relevant factor. I can't commit to you right now for reasons that we've talked about before, but I do ensure you of my integrity and that I would take that question very seriously," she said.