"Advocacy campaigns are central to unions' efforts to impact labour rights beyond unionized workplaces. Social media and on‐the‐ground campaign dynamics are intimately related. Thus, if unions can become leaders on social media, they could have more impact on campaign framing and mobilizing. Drawing on primary data and applying a sequential mixed method, we analyse unions' ability to emerge as opinion leaders in Twitter dialogues on the Fight for $15 (FF$15) campaign. We track FF$15‐related activities of Twitter profiles over seven months and compare union actions to those of others along three dimensions: level of activity, prevalence of tweeting versus retweeting and endorsement within FF$15 community and in the Twitter universe. Regression results show unions prefer advancing their own ideas over supporting those of others, and their messages are more endorsed than others' messages in the Twitter universe. In‐depth interviews and a focus group reveal that while their actions are slow and conservative, unions can count on internal support and institutional reputation to gain leadership. The article concludes by noting the implications of the findings for unions' strategies to become opinion leaders on social media."

Support: Digital