Matt Bruenig of the left-wing People’s Policy Project and a sometime contributor to The Atlantic is an ardent young Sandersista. Like most vicious ideologues, he reserves his most intense loathing not for those who are opposite him politically but those adjacent, in this case Democrats who support more centrist candidates, especially those working for former New York Mayor Mike Bloomberg. “It’s very important for us to create a blacklist of every operative who works on the Bloomberg campaign,” he wrote on Twitter, before deleting the post.

David Klion of Jewish Currents also has warned his fellow Democrats that those who back the wrong horse are going to be blacklisted. “It’s a mercy we’re warning you now,” he wrote on Twitter.

Klion presents a funny case: He wants to make a blacklist, but can’t quite get either the “black” or the “list” parts right. He organized a social-media harassment campaign targeting a Nigerian supporter of Pete Buttigieg, insisting — falsely and without evidence — that the black man in his sights was actually a white woman affiliated with the Buttigieg campaign. He has since been publicly corrected and confessed his error. But that is an old story with Democrats of Klion’s stripe: White liberals operate under the assumption that the role of black liberals is to do what white liberals tell them to do.