Sunday on CBS’s “Face The Nation,” Sen. Bernie Sanders (I-VT) said former Vice President Joe Biden should apologize for his comments about working with segregationist.

Partial transcript as follows:

BRENNAN: Congressman John Lewis the civil rights icon said this week that Joe Biden’s comments about in the past having done some work alongside and with segregationists wasn’t offensive. Why do you disagree?

SANDERS: Well look, Joe was a friend of mine as John is a friend of mine, all that I- all that I say is that I think Joe owes the country an apology on that and that it is one thing to work with people in the Senate as you have to do, as every senator does, I do, with people who have fundamental disagreements with. That’s one thing. You do that. That’s your job, but it’s another thing to kind of extol that those relationships and also to see civility in a sense as an end unto itself. We all want civil discourse in this country. But that’s not the end. You cannot be extolling people who really were part of a disgusting system that oppressed and terrorized millions of African-Americans in this country.

BRENNAN: But don’t you think he believes those things?

SANDERS: Yeah, do I believe- if your question is I think Joe Biden is a racist? Absolutely not. No I don’t. Not for a second. Joe is a friend of mine. I like Joe and I hope very much that this campaign will be about the real issues facing the American people and not, you know, ugly attacks.