In the week leading up to the first televised debates for 2020 Democratic hopefuls, front-runner Joe Biden has drawn ire from fellow candidates over remarks he made at a fundraiser, in which he described his ability to work with segregationists from the South during the early part of his political career.

Speaking at a private event in New York, on Tuesday, June 18, Biden shared a story about two senior senators he worked with when he first joined the Senate in 1973. One was Sen. James O. Eastland from Mississippi, a well-known and outspoken white supremacist during the civil rights movement of the 1960s and early ’70s. The other was Sen. Herman Talmadge from Georgia, also a staunch supporter of segregation, who served in the Senate for 24 years from 1957 to 1981.

“I was in a caucus with James O. Eastland,” Biden described. “He never called me boy. He always called me son.” Biden then went on to describe Talmadge as “one of the meanest guys I ever knew.”

In explaining what it was like to work in the Senate in those days, Biden recalled, “Well guess what? At least there was some civility. We got things done. We didn’t agree on much of anything. We got things done. We got it finished. But today, you look at the other side and you’re the enemy. Not the opposition, but the enemy. We don’t talk to each other anymore.”

Biden intended his remarks to be taken in passing and to speak to his ability to reach compromise and consensus with congressional leaders who shared starkly different viewpoints. This is a skill, he has claimed, that will make him effective in today’s divisive political climate and may set him apart from other candidates running for the 2020 Democratic nomination.

Biden’s remarks, however, quickly drew sharp criticism from other prominent Democrats who found them to be racially insensitive. Sen. Cory Booker (D-N.J.) immediately asked Biden to apologize. “You don’t joke about calling black men ‘boys,’” he said. “Men like James O. Eastland used words like that, and the racist policies that accompanied them, to perpetuate white supremacy and strip black Americans of our very humanity.”

Sen. Kirsten Gillibrand (D.-N.Y.), in an interview on MSNBC, agreed that Biden should apologize. Sen. Kamala Harris (D-Calif.) also publicly criticized the former vice president, describing his remarks as “misplaced and frankly misinformed.”

The public controversy surrounding Biden’s comments may reveal not only increasing pressure on the candidates, as they begin to compete in earnest for the 2020 nomination, but also a battle over the identity of the new Democratic Party. Democrats are far from unified as they face the 2020 election cycle. Political perspectives range from supporting Bernie Sanders, as a left-leaning ‘democratic-socialist,’ to Biden’s more centrist approach.

However, the controversy may also reveal more of a cultural divide between the social progressivism represented by younger candidates, such as Harris and Booker, and a more traditional view of establishment figures like Biden. Though Biden is the current front-runner and considered the elder statesman among 2020 hopefuls, some Democrats appear to question Biden’s cultural sensitivity and ability to be socially progressive.

See if this becomes a clearer theme among Democrats as the candidates for 2020 begin to debate one another in earnest next week.