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, and 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.
Morris, Charles E., III. "Pink herring & the fourth persona: J. Edgar Hoover's sex crime panic." Quarterly Journal of Speech 88/2 (2002): 228-244. doi:10.1080/00335630209384372.
Rowland, Robert C. The Rhetoric of Donald Trump : Nationalist Populism and American Democracy. Lawrence, Kansas: University Press of Kansas, 2021.
Schmitt, Casey. “A Tale of Two Eastwoods: Iconographic Persona and Rhetorical Ethos in Clint Eastwood’s ‘Halftime in America’ and RNC 2012 Address.” Persona Studies 2, no. 1 (2016): 41–54.
Wander, Philip. "The third persona: An ideological turn in rhetorical theory." Central States Speech Journal 35/4 (1984): 197-216. doi: 10.1080/10510978409368190.
Ware, B. L., and Wil A. Linkugel. "The Rhetorical Persona: Marcus Garvey as Black Moses." Communication Monographs 49 (1982): 50-62.