--- - |2 Abstract In two studies, we examine how different processes might underlie the political mobilization of individuals with marginalized versus privileged identities for left‐wing activism (LWA) versus right‐wing activism (RWA). In the first study, with a sample of 244 midlife women, we tested the hypotheses that endorsement of system justification beliefs and social identities were direct predictors of political activism, and that system justification beliefs moderated the mobilization of social identities for activism on both the left and the right. We found that system justification predicted RWA only among those who felt close to privileged groups; the parallel reverse effect did not hold for LWA, though rejection of system‐justifying beliefs was an important direct predictor. In Study 2, we replicated many of these findings with a sample of 113 college students. In addition, we tested and confirmed the hypothesis that LWA is predicted by openness to experience and is unrelated to RWA, but not that openness plays a stronger role among those with marginalized identities. These two studies together support our overall hypothesis that different personality processes are involved with political mobilization of privileged and marginalized individuals on the right and the left. - Analyses of Social Issues and Public Policy, Volume 17, Issue 1, Page 161-183, December 2017.