The concept of "persona" in rhetoric largely follows Ed Black's landmark essay, "The Second Persona."
Sources
Black, Edwin. "The Second Persona." Quarterly Journal of Speech 56 (1970): 109-119.
Doss, Erin, adn Robin E. Jensen. "Balancing Mystery and Identification: Dolores Huerta's Shifting Transcendent Persona." Quarterly Journal of Speech 99/4 (2013): 481-506.
Hogan, J. Michael, and Glen Williams. "Republican Charisma and the American Revolution: The Textual Persona of Thomas Paine's Common Sense." Quarterly Journal of Speech 86 (2000): 1-18.
Kirkpatrick, Walter G. "Bolingbroke and the Opposition to Sir Robert Walpole: The Role of a Fictitious Persona in Creating an Audience." Central States Speech Journal 32 (1981): 12-23.
Ware, B. L., and Wil A. Linkugel. "The Rhetorical Persona: Marcus Garvey as Black Moses." Communication Monographs 49 (1982): 50-62.