Justice Democrats went after black incumbents in '16, '18 and '20. That's the group that backs Sanders, Nina Turner and AOC.
And it pissed Jim Clyburn off.
And that is, in large part, is why Bernie Sanders got his ass handed to him on a platter in 2020. Clyburn put his aim on him, and black voters turned out for Biden. OK, maybe not so much FOR Biden as to ensure Sanders had no chance at the nomination.