A week before the first debate, some Democratic hopefuls are taking shots at each other — especially at former Vice President Joe Biden, whose speech about his friendships with segregationists seemed to make him vulnerable to attack from the other candidates, all of whom are trailing him in the polls.

Sen. Cory Booker (D-NJ), who has so far branded himself with a buoyant optimism and reluctance to adopt a pugilistic posture against President Donald Trump, sharply rebuked Biden for the comments.

He started out with some simple Twitter shade.

Soon after, he followed up with a fuller statement, asking Biden for an “immediate apology.”

Cory Booker has put out a statement on Joe Biden’s comments touting his work with segregationist senators. Booker says he’s “disappointed that (Biden) hasn’t issued an immediate apology for the pain his words are dredging up for many Americans. He should.” pic.twitter.com/n7hMS8E4NW — Rebecca Buck (@RebeccaBuck) June 19, 2019

New York City Mayor Bill de Blasio also reacted with anger, posting a picture of his biracial family and asserting that “it’s past time for apologies” from Biden.

It’s 2019 & @JoeBiden is longing for the good old days of “civility” typified by James Eastland. Eastland thought my multiracial family should be illegal & that whites were entitled to “the pursuit of dead n*ggers.” (1/2) pic.twitter.com/yoOOkpaTX2 — Bill de Blasio (@BilldeBlasio) June 19, 2019

During a fundraiser Tuesday evening in New York, Biden touted his ability to work with others by invoking Sens. James Eastland (D-MS) and Herman Talmadge (D-GA), both staunch segregationists. Speaking about Talmadge, Biden noted the late senator’s meanness but said “at least there was some civility. We got things done. We didn’t agree on much of anything. We got things done.”

Biden wasn’t the only one on the receiving end of some heat from his peers.

Sen. Bernie Sanders (I-VT) took an almighty swipe at Sen. Elizabeth Warren (D-MA), implying that she’s in bed with corporate interests.

The cat is out of the bag. The corporate wing of the Democratic Party is publicly “anybody but Bernie.” They know our progressive agenda of Medicare for All, breaking up big banks, taking on drug companies and raising wages is the real threat to the billionaire class. https://t.co/zimci7JRO6 — Bernie Sanders (@BernieSanders) June 19, 2019

Warren’s camp has not yet responded.