Social movements struggle to gain acceptance as legitimate actors so that they can raise money, recruit members, and convince politicians to meet their demands. We know little, however, about how this legitimacy is granted by various political authorities, in part because legitimacy is often poorly operationalized. To operationalize legitimacy, I revise Charles Tilly's () classic concept of WUNC displays (i.e., public presentations of worthiness, unity, numbers, commitment) to assess how political authorities legitimize social movements. I analyze original data on the coverage the Tea Party and Occupy Wall Street received from 20 elite political blogs during a critical event early in each movement's development. I find that liberal and conservative blogs both use the same aspects of worthiness (and not unity, numbers, or commitment) to endorse their preferred movement but different aspects of unworthiness to denounce the movement they opposed. Conservative outlets were more partisan on both accounts. This suggests that these blogs' shared status as distinctly partisan political outsiders produces a similar, but not identical, relationship with social movements. While both sets of blogs legitimize and delegitimize a movement based on its specific strengths and weaknesses, conservative blogs act more as a partisan bullhorn and liberal blogs act more as a forum for debate.