While the effects of climate change will impact most Americans, they will likely have a disproportionate influence on the socioeconomic well-being of marginalized communities. Few researchers, however, have investigated public support for policies aimed at ameliorating climate-related disparities. Fewer still have considered how political and (critically) pre-political psychological dispositions might shape environmental justice concern (EJC) and subsequently influence policy support—both of which, I argue, could present roadblocks for effective climate communication and policy action. In this registered report, I (1) propose and validate a new measure of EJC, (2) explore its political correlates and pre-political antecedents, and (3) test for a link between EJC and policy support. In addition to psychometrically validating the EJC scale, I find that pre-political value orientations are associated with EJC, which, in turn, mediates the effects of pre-political values on taking action to mitigate the unequal effects of climate change.