Drawing on interviews with leaders of the effort to promote the 2016 Bernie Sanders U.S. presidential candidacy on social media, this study contrasts the structure and content of various organizational networks to map the hybrid ecosystem of the contemporary digital campaign. While the “official” Sanders organization built applications to transform supporters into a tightly controlled distribution network for its social media messaging, this was complemented by “unofficial” grassroots networks that circulated more informal and culturally oriented appeals. The latter are classified according to the models of organizationally enabled and self‐organized connective action in digital social movements, with structural differences in oversight and moderation that suggest varying levels of creative autonomy for citizens and reputational risk for the associated campaigns.