As Kamala Harris was giving her vice presidential nomination speech, President Trump called to mind tensions between Democratic nominee Joe Biden and his running mate that played out during the primary season.

And as former President Barack Obama delivered his own address during the Democratic Convention, the president questioned why Obama had waited so long to endorse his former running mate.

“BUT DIDN’T SHE CALL HIM A RACIST???” Trump wrote on Twitter as the third night of the convention concluded with Harris’ remarks. “DIDN’T SHE SAY HE WAS INCOMPETENT???”

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“WHY DID HE REFUSE TO ENDORSE SLOW JOE UNTIL IT WAS ALL OVER, AND EVEN THEN WAS VERY LATE? WHY DID HE TRY TO GET HIM NOT TO RUN?” Trump wrote as Obama delivered a speech which, in a rare move for the stately former president, called his successor out by name.

"HE SPIED ON MY CAMPAIGN, AND GOT CAUGHT!"  Trump added later. 

Obama did not endorse Biden until April, when he was all but assured the nomination. Bernie Sanders had already dropped out of the race and endorsed Biden. There were reports of tension between Obama and Biden all throughout the campaign trail, with The New York Times reporting Obama told Biden last August “you don’t have to do this.” One Democrat who spoke with Obama said he reportedly told him: “Don’t underestimate Joe’s ability to f--k things up.”

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While Harris has not called Biden "a racist," she did condemn the former vice president for bragging of his work with segregationist senators last summer during the height of primary debates.

Biden touted his ability to “get things done” decades ago by working with Southern segregationist senators.

"It concerns me deeply,” Harris told Fox News in 2019 of Biden’s comments.

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

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Later, Harris made her mark, if short-lived, on the primary campaign trail in a personal moment when she called her now-running mate out for his past stance against bussing.

"There was a little girl in California who was part of the second class to integrate her public schools and she was bused to school every day. That little girl was me," Harris, of Indian and Jamaican descent, said at the time.