Recent data reveals that some White Americans perceive increasing levels of discrimination against their racial ingroup (i.e., reverse racism) and are resentful toward racial minorities (i.e., racial resentment). Using the theoretical framework of the Socially Mediated Stereotyping Model, the present research examines how social media use and political identity collectively influence these perceptions. A three-wave longitudinal study finds that both Time 1 engagement with politics on social media (negatively) and a more conservative political identity (positively) influence Time 2 racial resentment, which subsequently increased Time 3 beliefs in reverse racism. Additional tests of indirect effects find a significant negative relationship of engagement with politics on social media and a marginally significant positive relationship of higher conservative political identity on reverse racism via racial resentment. These results reflect how social media use and social identity-based motivations affect perceptions related to existing group hierarchies.