This essay documents one small but intense episode in the historic presidential election of 2008—the primary campaign waged in Hispanic South Texas between Barack Obama and Hillary Clinton. Told from the perspectives of out-of-state volunteer and rhetorically trained participant-observer, it depicts rhetorical scenes on the ground, partly created by the author, and worked out through embodied, Anglo-Hispano interaction. Beyond documenting the campaign at its grassroots, the essay is also a performative criticism of the coproduced rhetorical dramas, an exercise in rhetorical hermeneutics, and a contribution to interpretive rhetorical theory. It introduces the concept of “Mercurian rhetoric” as a category for mobile border-crossers and translators, and uses it as an interpretive pathway for charting the Obama campaign and resistances to it on the ground. Building from Michael McGee and Thomas Benson, the essay links criticism, fieldwork, and rhetorical production, and makes a case for embodied, neo-sophistic Mercurian rhetoric as practice and ideal.