Maybe I'm mistaken, but I was under the impression that Sanders supported "Black Lives Matter"? I thought he gave the protesters the stage and let them speak because he believes in their cause. Maybe I'm going out on a limb here, but I don't think the author is a big fan of Sanders.
The "ideas" section is Time's version of open.salon.com or huffington Post- the content is barely curated. They'll give it over to just about anyone who can type.