We live at a moment in some ways not unlike the 1890s and early twentieth century, when state governments, with the acquiescence of the Supreme Court, stripped black men of the right to vote and effectively nullified the constitutional promise of equality. “Principles which we all thought to have been firmly and permanently settled,” Frederick Douglass observed, were “boldly assaulted and overthrown.” As history shows, progress is not necessarily linear or permanent. But neither is retrogression.      By themselves, the constitutional amendments that emerged from the Civil War cannot address all the legacies of slavery. Sumner remarked of the Thirteenth Amendment that rewriting the Constitution was not an end in itself but “an incident in the larger struggle for freedom and equality.” But the Reconstruction amendments remain, in the words of one Republican newspaper, “a declaration of popular rights.”  They retain unused latent power that, in a different political environment, may yet be employed to implement in new ways the Reconstruction vision of equal citizenship for all.