WATCH: Jake Tapper calls out Jon Ossoff for falsely accusing Kelly Loeffler of campaigning with a Klansman

In December, Ossoff said that Sen. Loeffler was "campaigning with a Klansman," referring to a Dec. 11 picture Loeffler unknowingly took with a former member of the Ku Klux Klan. Loeffler stated unequivocally that she did not know of the man's affiliation.

"That's not true," Tapper said, calling Ossoff out. "It is true that a former member of the Klan took a photo with Senator Loeffler at a campaign event. Her campaign says she didn't know who she was at the time and she has condemned him."

"I'm sure you've taken photos with thousands of strangers. Isn't it important for candidates to tell the truth," Tapper pressed Ossoff.

Ossoff responded, doubling-down, "It is, and its even more distressing that this isn't an isolated incident. Kelly Loeffler has repeatedly posed for photographs and been seen campaigning alongside radical white supremacists."

"Her campaign has consisted almost entirely of racist attacks on the Black Lives Matter movement and on the black church," he continued.

The photo shows Loeffler posed with Chester Doles, a white supremacist, at a recent campaign event in Dawsonville, Ga. The Atlanta Journal-Constitution reported that Doles is a member of the Ku Klux Klan and the neo-Nazi National Alliance. Doles posted the picture on VKontakte, the Russian social network, on Friday with the caption: "Kelly Leoffener [sic] and I. Save America, stop Socialism!"

"Kelly had no idea who that was, and if she had she would have kicked him out immediately because we condemn in the most vociferous terms everything that he stands for," Loeffler campaign spokesman Stephen Lawson told the Associated Press on Sunday.

Lawson told the DCNF Thursday that Twitter should have flagged Ossoff's tweet and taken it down since it's "a blatant lie." Twitter declined to flag the tweet.

Ossoff is running against incumbent David Perdue for one of two coveted Senate seats in Georgia. Loeffler is running against Rev. Raphael Warnock. Warnock and Ossoff have teamed up against the two incumbents in an attempt to not only flip Georgia's senate seats blue, but the nation's Senate as well.