Many scholars have argued that rhetorical theory and pedagogy should return to the neo‐classical and agonistic theory and pedagogy of the antebellum era. The ability of proslavery ideology to dominate political and rhetorical practice, however, troubles any easy equation between that pedagogy and practice. This article argues that agonism was hindered by the rhetoric of the improbable cause, a tragic metanarrative of novels like Nick of the Woods, which served as a defense of slavery and slaveocracy, without even mentioning the word, through reinforcing a foundation for that system. This view served to rationalize a system that had a dreamy, noble, and tragic ethos that was actually protected and supported by a brutal practicality; left out is something in the middle, the practical but principled argument about long‐term politics.

Abstract John Quincy Adams's speech on behalf of the kidnapped Africans aboard the slave ship Amistad points to a troubling dilemma in rhetoric: that the power of rhetoric is limited by the audience's perception of what is plausible, and that can, as in the case of the Amistad argument, mean that outrageously unjust but intransigent and powerful interests set the limits of discourse. If rhetorical theory promotes decorum, what is the place of principled dissent and sincere outrage?