Ever Increasing "BS + Mega BS" from the 3 B's (Biden, Bloomberg, & Buttigieg): Sanders under fire in South Carolina Ads

“But back in Washington, there was one guy with another plan,” then Sanders audio: “I think it would be a good idea if President Obama faced some primary opposition.” (Part of a $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 

This tactic backfired badly in Nevada; so try it again in South Carolina?