MIAMI — As her fellow Democrats talked over one another amid a discussion of race and policing, Senator Kamala Harris interrupted and told the moderators of Thursday night’s presidential debate that she’d like to speak “as the only black person on stage.”
Then she delivered a powerful blow to the field’s front-runner, former vice president Joe Biden — just one of many attacks the 76-year-old would endure throughout the course of a night that raised doubts about the stability of his spot on the top of the polls.
Harris sharply criticized Biden’s record on race, but other rivals questioned his age, record on immigration, and other aspects of his candidacy as the former vice president struggled to defend himself during the two-hour debate among 10 candidates.
“I do not believe you are a racist,” Harris told Biden, before tearing into his recent comments highlighting his working relationships with segregationist senators as an example of the bipartisanship he wants to bring back to Washington.
“It was hurtful to hear you talk about the reputations of two United States senators who built their reputations and career on segregation of race in this country,” she said. “And it was not only that, but you also worked with them to oppose busing.”
Harris described the life of “a little girl in California who was part of the second class to integrate her public schools” at a time when Biden opposed federal intervention to force communities to use busing for that purpose.
“And she was bused to school every day,” Harris said. “And that little girl was me.”
Biden forcefully defended his record, saying that his position had nothing to do with Harris’s personal experience as a child. “I did not praise racists,” he said, adding she had “mischaracterized” his position “across the board.”
But then he trailed off when enumerating his record on civil rights. “Anyway, my time is up. I’m sorry,” Biden said awkwardly.
The heated exchange stood out for its emotion as Harris, who has yet to break into the uppermost tier in polls, took aim at Biden as part of an overall standout performance. At an earlier moment, Harris intervened as the candidates talked over each other, telling them to quiet down.
“OK guys, you know what -- America does not want to witness a food fight. They want to know how we’re going to put food on the table,” she said, triggering the loudest applause of the night.
Biden, who said he’s running to “restore the soul of the nation,” has an average lead of 15 percentage points in national polls, and many of his rivals have taken veiled and not-so-veiled shots at him before the debate.
But the animosity was vivid on stage, with even minor candidates winning a few precious minutes of airtime by taking him on from their spots at the edges of the stage.
It’s unclear if all the attacks will be enough to knock a few points off Biden’s imposing lead, or whether Harris stood out enough to move up in the polls.
That dynamic made for a sharp contrast from the more restrained tone of the first debate the previous night, when candidates went out of their way not to criticize each other. Thursday night’s candidates were more restive, straining at the 60-second limits they had to answer their questions, and grabbing for more time wherever they could.
Representative Eric Swalwell lobbed a zinger at Biden from his spot at the outer edge of the stage.
He quoted Biden from his 1988 presidential run saying it was time for the next generation to get its turn.
“Joe Biden was right when he said it was time to pass the torch to Americans 32 years ago and he’s right today,” Swalwell said, as Biden chuckled.
“I’m still holding onto that torch,” Biden retorted, then highlighted his plans for improving education.
For a moment, the other candidates tried to break in and make their own points about the Democratic front-runner’s age.
“As the youngest guy on the stage,” South Bend, Ind., Mayor Pete Buttigieg interjected, as Senator Kirsten Gillibrand yelled, “before we move on!”
Biden and liberal stalwart Senator Bernie Sanders of Vermont sucked up much of the oxygen in the early stages of the debate, as both men laid out starkly different visions for America.
On the issues of health care, college, and immigration, Sanders cast himself as the true progressive who would stand up to monied interests and recalibrate the nation’s staggering wealth inequality issue, while Biden favored a more gradual approach of building on Barack Obama’s legacy.
“The issue is who has the guts to take on Wall Street, to take on the fossil fuel industry, to take on the big money interests,” Sanders said.
Biden frequently looked back into history to cast himself as the only candidate on stage who could actually put plans into action. He said the Obama administration had presided over a drop in migrants coming to the United States.
“We all talk about these things,” Biden said. “I did it, I did it.”
Later, he called himself “the only person who beat the NRA” because he ushered the Brady background check bill to passage in 1993 over the objections of the National Rifle Association.
He also defended his record voting for the Iraq War, pointing out that he was strongly for bringing it to a close as vice president. “I was responsible for getting 150,000 combat troops out of Iraq and my son was one of them,” he said.
Biden and Sanders weren’t the only ones to receive criticism Thursday night. Former governor John Hickenlooper of Colorado and Swalwell also attacked Buttigieg after a black man was shot by a South Bend police officer earlier this month. “You should fire the chief,” Swalwell said, as Buttigieg said he was taking responsibility. “It’s a mess and we’re hurting,” the mayor said.
And several candidates also criticized Sanders’ positions on Medicare for All, which he conceded at the beginning of the debate would raise taxes for the middle class to provide universal health care, as well as for his plan to offer free college and debt cancellation for everyone.
“I just don’t believe it makes sense to ask working-class families to subsidize even the children of billionaires,” Buttigieg said.
Hickenlooper, a moderate, also aimed his fire at Sanders’ plan. “I believe health care is a right and not a privilege but you can’t expect to eliminate private insurance for 180 million people, many of whom don’t want to give it up,” he said.
Liz Goodwin can be reached at email@example.com. Follow her on Twitter @lizcgoodwin. Jess Bidgood can be reached at Jess.Bidgood@globe.com. Follow her on Twitter@jessbidgood