Vice-presidential nominee Sen. Kamala Harris, D-Calif., asked Barrett whether she agrees with the majority opinion written by Chief Justice Roberts in Shelby County v. Holder stating that voter discrimination still exists -- but Barrett wouldn’t answer what Harris said she thought was an easy question. 

"Senator Harris, I will not comment on what any justice said, an opinion, whether an opinion is right or wrong, and endorse that proposition," Barrett said.

"So, do you call it a proposition or fact? Are you saying you cannot agree with the fact?" Harris pressed.

"Senator, I'm not exactly sure what you're getting at with asking me to endorse the fact or whether any particular practice constitutes voter discrimination. I'm very happy to say that I think racial discrimination still exists in the United States, and I think we've seen evidence of that this summer," Barrett said.

"These are very charged issues that have been litigated in the courts, and so I will not engage on that question," she added, when Harris continued on voter and racial discrimination.

Dissatisfied with her response, Harris pivoted to science and climate change and, after a series of simple questions including whether she believes in COVID-19, asked Barrett if she believes climate change is real. 

"You have asked me a series of questions like that are completely uncontroversial like whether COVID-19 is infectious, whether smoking causes cancer, and then trying to analogize that to eliciting an opinion from me that is a very contentious matter of public debate, and I will not do that," Barrett said.

She didn't offer the information, but Barrett has previously disclosed she was diagnosed with COVID-19 over the summer.

Sen. Cory Booker, D-N.J., said he was disappointed when Barrett told him she had not read any studies or articles, books, law review articles or commentary regarding racial disparities present in our criminal justice system. 

Barrett eventually said her knowledge of these issues roiling the country comes from conversations at Notre Dame. 

"I would say what I have learned about it has mostly been in conversations with people at Notre Dame. As at many different universities it’s a topic of conversation in classrooms, but it's not something that I can say yes I've done research on this and read," she said. 

Following questioning from Booker, Sen. Mike Crapo, R-Idaho gave Barrett a chance to defend herself from the "implication" that she would "not be sensitive to the need for equal justice for all." 

Barrett reaffirmed that she "abhors" racial discrimination and said she would want all of her children, "especially Vivian and John Peter" -- her two adopted children -- to know that she "unequivocally condemns racism."

-ABC News’ Trish Turner and Allie Pecorin

The late Justice Ruth Bader Ginsburg and her legacy is a major presence at the confirmation hearing.

Both Republicans and Democrats have invoked the late justice in their questioning -- but her presence was shown in more visual ways, too.

For the third day in a row, Sen. Mazie Hirono, D-Hawaii, sported a mask with images of the late icon. 

Sen. Chris Coons, D-Del., had placed a photo of Ginsburg in front of him for his questioning.

Not far outside the committee room on Capitol Hill, people for and against Barrett’s nomination protested outside the Supreme Court building, with many holding signs nodding to her signature collar.