Political theorists and social scientists alike agree that passions matter for politics, but disagree about which passions matter most and how they contribute to political flourishing. I make the case that resentment, contrary to its traditional associations with violence and injustice, in fact makes us alive to the suffering of others and leads us to aid them in seeking restitution. When we adopt the resentments of others by sympathizing with them, we implicitly recognize their equal moral and political status, too, key commitments of liberalism. I argue that liberals of all stripes should embrace sympathetic resentment as a proper moral motive for justice.