Rep. Bobby Rush (D-IL) blasted former Vice President Joe Biden over his praise for segregationists on Friday, saying he had proven “woefully ignorant” of the “black American experience.”

Rush, a member of the Congressional Black Caucus (CBC) and former civil rights activist, said he was surprised that Biden had proven so obtuse after having served under President Barack Obama for two terms.

The Illinois Democrat told Politico:

You would think that after eight years of serving as Vice President under President Obama, Biden would get it, that his frame of reference would be more audacious for the future and less on the obvious incrementalism of the past. With his statement he has demonstrated that he is wholly out of touch and woefully ignorant of the nuances of the black American experience and that is, in itself, beyond disappointing.

Rush is one of the only members of the CBC to come out and denounce Biden for praising the “civility” of two segregationist Democrats, Herman Talmadge (D-GA) and James Eastland (D-MS), he served with in the U.S. Senate. Biden made the remarks at a fundraiser in New York City on Tuesday and has remained defiant in the face of mounting controversy.

Other members of the CBC have been less willing to take the former vice president to task for his comments.

“I don’t think the remarks are offensive,” Rep. John Lewis (D-GA), another former civil rights activist, told reporters outside the Capitol on Friday. “During the height of the civil rights movement, we worked with people and got to know people that were members of the Klan, people who opposed us, even people who beat us, and arrested us and jailed us.”

Rep. Jim Clyburn (D-SC), the House Majority Whip and the highest ranking African-American in Congress, expressed a similar sentiment on Wednesday.

“I worked with Strom Thurmond all my life,” the South Carolina congressman said. “You don’t have to agree with people to work with them.”

Clyburn has recently been accused of “tacitly endorsing” Biden for the Democrat presidential nomination, despite promising to stay neutral.

Apart from Rush, Sen. Cory Booker (D-NJ) is one of the only other CBC members to criticize Biden publicly and demand he apologize.

Booker, a fellow 2020 candidate, said on Wednesday:

Vice President Biden’s relationships with proud segregationists are not the model for how we make America a safer and more inclusive place for Black people, and for everyone. 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.

Biden, who both downplayed his support for civil rights and exaggerated his role in the movement during his 1988 presidential bid, responded by saying if anyone was owed an apology, it was him.

“Cory should apologize. He knows better,” Biden said. “There’s not a racist bone in my body. I’ve been involved in civil rights my whole career, period, period, period.”