Former Vice President Joe Biden faced scorching criticism Wednesday from his Democratic primary rivals for invoking his ability decades ago to work with two segregationist southern senators to “get things done.”

Two of the three black candidates running for the White House -- Sens. Cory Booker of New Jersey and Kamala Harris of California -- raised serious concerns.

Booker said in a statement he was “disappointed” Biden had yet to issue an “immediate apology.”

BIDEN HOLDING TOP-DOLLAR FUNDRAISERS AMID ATTACKS FROM RIVALS

“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.

Harris told Fox News while riding an elevator on Capitol Hill that "it concerns me deeply."

She continued, "If those men had their way, I wouldn't' be in the United States Senate and on this elevator right now."

Another top rival for the nomination, Sen. Elizabeth Warren of Massachusetts, highlighted that "I'm not here to criticize other Democrats but it's never OK to celebrate segregationists. Never."

Hours earlier, New York City Mayor Bill de Blasio -- who’s married to an African American woman and has an interracial family -- slammed the former vice president on Twitter.

“It’s past time for apologies or evolution from @ JoeBiden. He repeatedly demonstrates that he is out of step with the values of the modern Democratic Party,” he wrote, posting an old photo of his family and saying one of the late senators Biden mentioned, James Eastland, thought his family should be "illegal."

Anita Dunn, a top Biden campaign adviser and surrogate who worked with Biden in the Obama White House, defended the former vice president's comments, telling NBC News that he "didn't praise them, he didn't praise their positions, he certainly didn't endorse their positions."

Similarly, adviser Symone D. Sanders tweeted that Biden "did not praise a segregationist. That is a disingenuous take."

Biden, the clear front-runner right now in the race for Democratic nomination, brought up the names of Sens. Eastland of Mississippi and Herman Talmadge of Georgia while speaking at a fundraiser Tuesday in New York City. Eastland and Talmadge, two senior members in the Senate when Biden arrived in the chamber in 1973, were firmly opposed to desegregation efforts.

“I was in a caucus with James O. Eastland,” the 76-year old Biden said as he briefly imitated the late senator’s southern drawl. “He never called me boy. He always called me son.”

And he called long-deceased Talmadge “one of the meanest guys I ever knew.”

But discussing the “civility” in the Senate during the 1970s, according to the pool report, Biden said: “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, the enemy. We don't talk to each other anymore.”

The comments were part of Biden’s repeated warnings against Democrats who feel it’s not worth trying to find compromise with Republicans on the numerous divisive issues that have brought Washington to a standstill. Biden’s message of bipartisanship has been derided by some of his rivals for the Democratic nomination.

It wasn’t the first time Biden’s mentioned his efforts to find common ground decades ago with senators like Eastland and Talmadge.

At a house party in Nashua, N.H., last month, Biden said that when he arrived in the Senate “all the old segregationists were there for Lord's sake….But after the fight was over, then you moved on and this is, like, I don't consider the opposition my enemy, they're the opposition.”

Dunn emphasized that the point Biden was making "is that you have to be able to work with people, even if they hold positions repugnant to you in order to make some progress."

And, she noted that Biden "took on Jim Eastland in the Judiciary Committee over the voting rights act and he won. And he won over and over again on the voting rights act in the course of his career. And I think anyone who served with Joe Biden, you know, whether it was in the Senate or whether they worked with him during his eight years as Barack Obama's vice president, knows that this is a man who is committed to equality and civil rights in this country."

Booker, in his statement, emphasized that you “don’t joke about calling black men ‘boys.’ 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.”



“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,” Booker added. “And frankly, I’m disappointed that he hasn’t issued an immediate apology for the pain his words are dredging up for many Americans. He should.”

Fox News reached out to Biden’s presidential campaign for comment, but has not yet received a response.

The political spotlight on Biden’s comments comes on Juneteenth, an American holiday that commemorates the June 19, 1865, announcement of the abolition of slavery in Texas. The holiday more broadly also marks the emancipation of those held in slavery throughout the Confederacy.

The pushback also marks Biden's second major dispute in recent weeks with his primary rivals, having recently faced criticism for his support of the Hyde Amendment, which bars the use of federal funds to subsidize abortions in most cases. He later reversed his stance.

Fox News' Jason Donner and Sam Dorman contributed to this report.