The use of fear in US presidential advertising campaigns has been pervasive since the 1960s but has become more extreme with every passing election. This thesis assesses how fear is used in presidential advertising campaigns and what circumstances make it most impactful on long-term judgment and opinions. The present work utilized prominent cognitive theories of judgment and persuasion to develop a new framework to assess the use of fear in advertising. Frameworks used were The Appraisal Tendency Framework (Lerner, Han & Keltner, 2007), The Elaboration Likelihood Model of Persuasion (Petty and Cacioppo 1986), The Prospect Theory (Kahneman et al, 2002), and The Protection Motivation Theory (Rogers et al. 1975). This new framework was used to assess the use and efficacy of fear in the advertising campaigns of the 1964, 1988, 2016, and 2020 US Presidential elections. The analysis suggests that when utilized in specific ways in advertising, fear may significantly impact voters and may very well have defined the outcomes of many elections. Simultaneously, it is argued that fear may not always be the deciding factor in an election, and in certain circumstances, it may not be enough on its own to win.