Joe Biden admitted Friday he wasn't ready to be attacked on the busing issue by Kamala Harris during last week's Democratic debate.

'Sure they were going to come after me. I was prepared for them to come after me, but I wasn't prepared for the person coming at me the way she came at me,' Biden told CNN of the debate confrontation. 'She knows me.'

He argued it's easy for someone to go back and take something in his long public record out of context.

Joe Biden admitted he wasn't ready to be attacked on the busing issue

Kamala Harris attacked him in last week's debate on the issue

'What I didn't see was people who know me. They know me well. It's not like somebody who just came out of the blue and didn't know anything. It's easy to go back 30, 40, 50 years, and take a context completely out of context,' he said.

He said he wouldn't attack rivals on their past.

'I get all this information about other people's past and what they've done and not done. I'm not going to go there,' he said.

The former vice president also tried to clarify his position on the busing issue.

'I was for voluntary bussing,' he said. 'The way to deal with that problem is what I did from the time I was a kid. I got out of law school, came back, had a great job as a public defender. I fought for putting housing in low-income housing in suburbia. I talked about eliminating red lining. I talked about school districts should be consolidated in ways that made sense.'

CNN host Chris Cuomo asked him: 'Why didn't you fight it like this in the debate?'

Biden blamed the 30 second time limit, which is the amount of time the candidates were allowed to respond.

'What didn't want was to get in the scrum. Do you think the American public looked at that debate, take me out of it, and thought, boy, I really liked the way that's being conducted?,' he said.

Biden and Harris brought their debate fight to Iowa on the Fourth of July as the two squabbled over the school busing issue and their campaign staff descended into a Twitter war on it.

The former vice president expressed frustration with his long-ago actions being brought to the forefront of the 2020 Democratic presidential primary campaign and the California senator had to clarify comments from the day before that made it appear she actually agreed with Biden on the issue.

It began when Harris said in Iowa on Wednesday that school busing issues - moving students from a low-income school district to a higher one - should be considered by school districts.

Joe Biden expressed frustration with his long-ago actions being brought to the forefront of the Democratic primary contest

Kamala Harris had to clarify comments from the day before that made it appear she actually agreed with Biden on school busing

That appeared to be a step back from federal mandate she seemed to support when she criticized Biden in their debate last week - a moment that went viral, boosted her campaign coffers by $2 million and raised her poll numbers.

'Busing is a tool among many that should be considered when we address the issue, which is a very current issue as well as a past issue, of desegregation in America's schools. So I think of busing as being in the toolbox of what is available and what can be used for the goal of desegregating America's schools. I believe that any tool that is in the toolbox should be considered by a school district,' she said.

Biden, campaigning in Iowa Thursday, said Harris was 'absolutely right,' on the issue.

But he refused to bite when a reporter asked if that sounded different from the position she articulated in their debate.

'Look, she's a good person. She is smart as can be. She feels strongly. It came out of nowhere. It didn't seem to be something at all consistent with anything I had been accused of before,' he said.

The former vice president said he had nothing to atone for on the school busing issue.

'I don't have to atone,' Biden said. 'My record stands for itself. I've never been accused by anybody ... of not being an overwhelming supporter of civil rights and civil liberties.'

The former vice president also said it was a 'new thing' to go back 40 or 50 years into someone's record and vowed he would not do the same against his rivals.

At 76, Biden is one of the oldest candidates in the race with a long record of public service. Few of his rivals have such a record - Bernie Sanders being the exception.

'This is kind of a new thing, you know we’re going back 40 or 50 years now to a vote,” he said.

“I’m not going to go back and talk about the record of anyone from 10, 20, 30 years ago,” Biden said, adding that “everything is lost in context.”

Meanwhile Harris had to clarify her earlier answer on the issue.

‘I’ve asked him, and have yet to hear him agree, that busing was court-ordered and mandated in most places in that era in which I was bused was necessary. He has yet to agree that his position on this, which was to work with segregationists and oppose busing, was wrong. Period,’ she said Thursday in Iowa.

‘Do we need a quick lesson in history? Which is that there were forces and individuals and supposed leaders in our country who actively worked against the integration of schools based on race. That is what was happening at the time. That’s why busing was mandatory at the time. Thankfully, fast forward today and we don’t have that challenge. We have other challenges that need to be addressed. But he has yet to agree that the position he took then was wrong, and he and I just disagree on that.’

But Biden's campaign took issue with Harris' original comment and his campaign communications director struck out at her via Twitter.

Biden holds a baby while marching in a parade in Iowa

Kamala Harris greets Iowa voters in the state Wednesday

'It's disappointing that Senator Harris chose to distort Vice President Biden's position on busing — particularly now that she is tying herself in knots trying not to answer the very question she posed to him!,' Kate Bedingfield wrote.

Harris' national press secretary snapped back.

'VP Biden said: “Who the hell do we think we are that the only way a black man or woman can learn is if they rub shoulders with my white child?” He called busing an “asinine concept.” C’mon. Y’all are better than this,' Ian Sams wrote.

Bedingfield responded by quoting Harris on her respect for Biden.

'Hi Ian! If we’re cherry-picking quotes on Twitter, what about this one from this January? Sen. Harris: “I think there are many people who would make a good president... I'm very fond of Joe Biden, so you're not gonna hear me criticize Joe Biden. I think he's a great guy,”' she wrote.

'She does think he’s a good guy. So do I. That’s why a simple “working with segregationists to stop busing 40 years ago was wrong, and I shouldn’t have done it” would be welcome,' Sams responded.

Other campaign staff weighed in.

Harris' communications director Lily Adams said one position's on the busing issue in the 70s cannot be compared to one's position on the issue now.

'The debate discussion was about opposing busing in 1970. It is now 40 years later in the year of our Lord 2019. Did you miss that?,' she tweeted in response to David Axelrod, the campaign manager for Barack Obama who wrote on his own social media account that it sounded like Harris was now taking Biden's position on the issue.

She went on attack Biden for flip-flopping on his support for the Hyde Amendment, the legislation that forbids federal funds for being used for an abortion, which the former vice president supported before announcing last month he opposed it.

'Remind me what his position on Hyde was a month ago? Honestly - this is very simple. The Q from the debate remains. Does the VP regret working with segregationists against busing in the 1970s or does he not? Then we can all get back to our July 4 BBQs!,' Adams wrote.

The contentious public back-and-forth gives an indication of the tensions brewing among Democratic contenders.

Harris moved up to second place in the latest Iowa poll after her debate performance.

During last week's Democratic debate, Harris tore into Biden for his opposition to a school busing program, which was designed to move students from lower-income neighborhoods into schools in better districts to integrate them.

She also confronted the former vice president on his comments about working with two segregationists in the Senate.

'I do not believe you are a racist. And I agree with you, when you commit yourself to the importance of finding common ground,' she said. 'But I also believe – and it’s personal, and I was actually very – 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.'

She then choked up for a second before talking about her schooling experience in Berkley, Calif.

'And it was not only that, but you also worked with them to oppose busing. And, you know, there was a little girl in California who was part of the second class to integrate her public schools, and she was bused to school every day.

'And that little girl was me. So I will tell you that on this subject, it cannot be an intellectual debate among Democrats. We have to take it seriously. We have to act swiftly. As Attorney General of California, I was very proud to put in place a requirement that all my special agents would wear body cameras and keep those cameras on.'

I WOULD LIKE TO SPEAK: Joe Biden 's praise for segregationists followed him to the Democratic presidential debate and exploded into a racial controversy after Kamala Harris lectured him on busing

Biden nearly froze on camera and stumbled in his response.

'It’s a mischaracterization, my position across the board, I did not praise racists. That is not true, number one. Number two, if we want to have this campaign litigated on who supports civil rights and whether I did or not, I’m happy to do that,' he said.

He then gave a long-winded answer defending his past record on civil rights.

'I was a public defender – I didn’t become a prosecutor. I came out and I left a good law firm to become a public defender, when in fact, when in fact my city was in flames because of the assignation of Dr. King, number one. Now number two, as the Vice President of the United States, I worked with a man who in fact, we worked very hard to see to it we dealt with these issues in a major, major way. '

He then addressed Harris' charge on busing.

'The fact is that – in terms of busing, the busing – I never – you would have been able to go to school, the same exact way, because it was a local decision made by your City Council.'

Harris told him that's why federal law, created by the body he was a part of, was needed.

Biden told her, 'The bottom line here is, look, everything I’ve done in my career, I ran because of civil rights, I continue to think we have to make fundamental changes in civil rights. And those civil rights, by the way, include, not only African Americans, but the LGBT community.'

Harris continued to put the screws to him. 'But Vice President Biden, do you agree today – do you agree today that you were wrong to oppose busing in American then? Do you agree?' she asked.

'No, I did not oppose busing in America. What I opposed was busing ordered by the Department of Education. That’s what I opposed,' he told her.

She told him, 'Well there was a failure of states to integrate public schools in American. I was part of the second class to integrate Berkeley California public schools almost two decades after Brown v. Board of Education.'

Biden again gave a long answer on his record before admitting his time was up.

'I have supported the ERA from the very beginning. I’m the guy that extended the Voting Rights Act for 25 years. We got to the place where we got 98 out of 98 votes in the United States Senate doing it. I’ve also argued very strongly that we in fact deal with the notion of denying people access to the ballot box. I agree that everybody wants that – in fact, they should – anyway, my time’s up. I’m sorry,' he said.