Photography by Ryan Pfluger in New York on September 21, 2015.
"You are the social media emperor!" said Hillary Clinton to DeRay Mckesson when he told her their goodbyes were being shared with the world on Periscope. The exchange followed a "tough, productive, and candid" October meeting, which he secured by tweeting to her, in advance of the presidential candidate's releasing a policy platform on social justice issues. After the police killing of Michael Brown in Ferguson, Mo., Mckesson left his school administrator job in Minneapolis to protest in St. Louis and many cities thereafter. His incisiveness, outspokenness, social media shrewdness, and ability to mobilize have helped make Black Lives Matter the most effective and formidable American protest movement this century.