MIAMI (Reuters) - Presidential candidate Kamala Harris dominated her Democratic rivals in a debate on Thursday, confronting front-runner Joe Biden on race and calling his remarks about working with segregationist senators “hurtful.”

In a breakout performance, the daughter of a black father from Jamaica and an Indian mother was at the center of several heated exchanges during the second night of debates among Democrats vying for the right to challenge Republican President Donald Trump in the 2020 election.

Harris said the issue of race was deeply personal for her. She noted she was bused to school as part of integration efforts in California, and she questioned Biden’s 1970s opposition to school busing.

The former prosecutor looked straight at Biden and demanded that he explain himself.

“I do not believe you are aracist. And I agree with you when you commit yourself to the importance of finding common ground,” said Harris, 54, a U.S. senator from California who has ranked fourth or fifth in most national polls among Democrats.

“But I also believe - and it’s personal and it was hurtful to hear you talk about the reputations of two United States senators who built their reputations and career on the segregation of race in this country.”

Biden, who was on the defensive throughout the night, has faced heavy criticism for his recent comments that he worked decades ago with two Southern segregationist senators as a way to get things done in the U.S. Senate.

He appeared shaken by the attack, but defended his record on civil rights and said his remarks had