Sanders calls on Biden to apologize for comments on segregationist senators

White House hopeful Sen. Bernie SandersBernie SandersPoll: Biden leads 2020 Democratic field by 15 points, followed by Sanders and Warren Warren introduces bill to cancel student loan debt for millions Democrats, advocacy groups urge Pompeo to abolish new 'unalienable rights' commission MORE (I-Vt.) called on 2020 front-runner former Vice President Joe BidenJoe BidenPoll: Biden leads 2020 Democratic field by 15 points, followed by Sanders and Warren Booker takes swipe at Biden criminal justice reform plan Panel: Has Joe Biden been wrong on everything for 40 years? MORE to apologize for touting his work with two segregationist senators.

“I agree with Cory BookerCory Anthony BookerBooker takes swipe at Biden criminal justice reform plan Democrats, advocacy groups urge Pompeo to abolish new 'unalienable rights' commission Biden announces plan to counteract mass incarceration MORE. This is especially true at a time when the Trump administration is trying to divide us up with its racist appeals,” Sanders tweeted, echoing an earlier call from Sen. Cory Booker (D-N.J.), another presidential candidate, for Biden to apologize.

Biden made the remarks at a Tuesday night fundraiser, where he recalled working with former Sens. James Eastland (D-Miss.) and Herman Talmadge (D-Ga.), who were both staunch segregationists.

“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,” Biden said.

A slate of 2020 Democrats condemned Biden over the remarks, including Sens. Booker, Kamala HarrisKamala Devi HarrisPoll: Biden leads 2020 Democratic field by 15 points, followed by Sanders and Warren Democrats, advocacy groups urge Pompeo to abolish new 'unalienable rights' commission Biden announces plan to counteract mass incarceration MORE (Calif.) and Elizabeth WarrenElizabeth Ann WarrenPoll: Biden leads 2020 Democratic field by 15 points, followed by Sanders and Warren Warren introduces bill to cancel student loan debt for millions Democrats, advocacy groups urge Pompeo to abolish new 'unalienable rights' commission MORE (Mass.) and New York City Mayor Bill de BlasioBill de BlasioBiden announces plan to counteract mass incarceration Lawyer says suspect in mob boss killing believed he was on mission from Trump Democratic strategist predicts most 2020 candidates will drop out in late fall MORE.

“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,” Booker said. “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.”

Though Biden has emerged as the crowded Democratic primary’s front-runner, progressives have weighed his centrist reputation and say he could be too eager to work with Republicans if elected.

Sanders, whose 2016 insurgent presidential campaign electrified the progressive base, is trying to eat into Biden’s lead in early national and statewide primary polls. Sanders consistently polls near the top of such surveys but has been consistently outpaced by the former vice president.

The two presidential contenders have mostly taken only veiled swipes at each other in the early stages of the nominating contest, though the criticisms could get more pointed as the primary drags out, particularly as the debates get underway.