Democratic presidential candidate Joe Biden is dismissing calls to apologize for saying that the Senate “got things done” with “civility” even when the body included segregationists with whom he disagreed.

His rivals for the 2020 nomination, including the two major black candidates in the race, roundly criticized Biden’s comments. But Biden didn’t back down Wednesday and was particularly defiant in the face of criticism from New Jersey Sen. Cory Booker, who said the former vice president should apologize.

Biden said Booker should apologize because the senator “should know better” than to question Biden’s commitment to civil rights.

“There’s not a racist bone in my body,” Biden said. “I’ve been involved in civil rights my whole career.”

Booker’s response: “I was raised to speak truth to power and that I shall never apologize for doing that. And Vice President Biden shouldn’t need this lesson,” he told CNN.

It’s becoming one of the most intense disputes of the primary, showing the hazards for Biden as he tries to turn his decades of Washington experience into an advantage. Instead, he’s infuriating Democrats who say he’s out of step with the diverse party of the 21st century and potentially undermining his argument that he’s the most electable candidate to take on President Donald Trump.

At a New York fundraiser Tuesday, Biden pointed to two long-dead segregationist senators, Democrats James Eastland of Mississippi and Herman Talmadge of Georgia, to argue that Washington functioned more smoothly a generation ago than under today’s “broken” hyperpartisanship.

“We didn’t agree on much of anything,” Biden said of the two men, who were prominent lawmakers when Biden was elected in 1972. Biden described Talmadge as “one of the meanest guys I ever knew” and said Eastland called him “son,” though not “boy,” a reference to the racist way many whites addressed black men at the time.

Yet even in that Senate, Biden said, “At least there was some civility. We got things done.”

Biden’s rivals quickly pounced.

“I have to tell Vice President Biden, as someone I respect, that he is wrong for using his relationships with Eastland and Talmadge as examples of how to bring our country together,” said Booker, who is African American.

New York City Mayor Bill de Blasio, a white man who is married to a black woman, tweeted: “It’s 2019 & JoeBiden is longing for the good old days of ‘civility’ typified by James Eastland. Eastland thought my multiracial family should be illegal.”

California Sen. Kamala Harris, who is black, said Biden was “coddling” segregationists in a way that “suggests to me that he doesn’t understand … the dark history of our country” — a characterization Biden’s campaign rejects.

Former Texas Rep. Beto O’Rourke said that for Biden “to somehow say that what we’re seeing in this country today is a function of partisanship or a lack of bipartisanship completely ignores the legacy of slavery and the active suppression of African Americans and communities of color right now.”

The tumult comes at a crucial point in the campaign. Biden is still recovering from controversy earlier this month when he angered many Democrats by saying he didn’t support federal taxpayer money supporting abortion. He later reversed his position.

He’s among the more than 20 candidates who will be in South Carolina this weekend to make their case to black voters at a series of events.

Meanwhile, most of the candidates will gather in Miami next week for the first presidential debate of the primary season. Biden will almost certainly face criticism for the comments.

He tried to defuse the tension by saying he was trying to argue that leaders sometimes have to work with people they disagree with to achieve goals, such as renewing the Voting Rights Act.

“The point I’m making is you don’t have to agree. You don’t have to like the people in terms of their views,” he said. “But you just simply make the case and you beat them without changing the system.”

He has received support from some black leaders. Louisiana Rep. Cedric Richmond, Biden’s campaign co-chairman and a former Congressional Black Caucus chairman, said Biden’s opponents deliberately ignored the full context of his argument for a more functional government.

“Maybe there’s a better way to say it, but we have to work with people, and that’s a fact,” Richmond said, noting he dealt recently with President Donald Trump to pass a long-sought criminal justice overhaul. “I question (Trump’s) racial sensitivity, a whole bunch of things about his character … but we worked together.”

Likewise, Richmond said, Biden mentioned Jim Crow-era senators to emphasize the depths of disagreements elected officials sometimes navigate. “If he gets elected president, we don’t have 60 votes in the Senate” to overcome filibusters, Richmond noted. “He could be less genuine and say, ‘We’re just going to do all these things.’ But we already have a president like that. (Biden) knows we have to build consensus.”

Biden also drew a qualified defense from Republican Sen. Tim Scott of South Carolina, the only black senator from his party.

Scott said that Biden “should have used a different group of senators” to make his point but that his remarks “have nothing to do with his position on race” issues. Scott said the reaction reflects an intense environment for Democrats in which the desire to defeat Trump means “anything the front-runner says that is off by a little bit” will be magnified.