Doctor of Philosophy (PhD)


Mass Communication

Document Type



From Scott Baio’s endorsement of Donald Trump to Sarah Silverman’s endorsement of Bernie Sanders and subsequent rejection of the “Bernie or Bust” crowd at the DNC, celebrities have habitually inserted themselves into the political sphere, however, there has been little empirical research on celebrity endorsements of political candidates. Rooted in branding theory, this study seeks to understand the effectiveness of celebrity political endorsements by utilizing advertising effectiveness models. The primary model, derived from work done by Amos, Holmes, and Strutton (2008), translates source factors of a celebrity product endorser to those of a celebrity candidate endorser, such as credibility, attractiveness, and trustworthiness. While in traditional advertising research, effectiveness is measured by outcomes such as brand attitude, and intention for product purchase, this study defines effectiveness in terms of attitudes toward the candidate, endorsement believability, recognition, and willingness to engage in electoral and online civic behaviors. After providing demographic information and information about digital media use and partisanship, participants were provided with a social media post, allegedly from a famous actor, endorsing a fictitious candidate and were asked to rate the actor on 21 attributes of a good endorser (source factors) and answer questions relating to their identification with the celebrity, perceptions of the celebrity-candidate fit, and their perceptions of the candidate’s viability in the election. They were subsequently asked to evaluate the candidate, the endorsement’s believability, recognize information from the endorsement, and indicate how likely they were to perform nine civic behaviors for the candidate. The data suggest that the endorser effectiveness model used by advertising researchers is useful for understanding the source factors and other considerations upon which celebrity political endorsement effectiveness is predicated. The study found that source factors vary in effectiveness between attitude, cognitive, and behavioral measures, leading to the conclusion that celebrity endorsers with different characteristics may be useful to political campaigns depending upon desired voter outcomes, particularly with regard to time during a campaign cycle.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Sylvester, Judith