Why did it take so long for the Sanders campaign to take on the Berniebro?

In October of 2015, Robinson Meyer wrote at The Atlantic about a phenomenon he was starting to observe among those who were #feelingthebern: The Berniebro. His piece marked (I think, and please correct me if I’m wrong) the introduction of the term to the political landscape, describing the primarily white, young men who spewed their enthusiasm for Bernie […]