“When we rallied together to defend our president and all the progress he made they had his back,” the narrator says. Then, panning to then vice president Joe Biden, the voice-over continues, “He had his back,” and moving to images of African American supporters at an Obama rally, says “And you had his back.”

The ad then shifts to a black and white image of Bernie Sanders.

“But back in Washington, there was one guy with another plan,” the narrator says before an audio clip is heard of Sanders saying, “I think it would be a good idea if President Obama faced some primary opposition.”

The ad is part of a broader $600,000 digital buy in South Carolina that the campaign is considering spinning into a broadcast ad.

“Bernie Sanders was seriously thinking about challenging our first African American president in a primary,” the narrator says, citing an Atlantic report entitled: “The Hidden History of Sanders’s Plot to Primary Obama.”

The Sanders campaign denies that Sanders ever had designs about mounting a primary campaign against Obama.

“This never happened. Bernie Sanders never considered a primary challenge to Obama,” deputy campaign manager Ari Rabin-Havt said in a statement. “Bernie was running for reelection in 2012 and that’s what he was focused on.”