The aim of this thesis is to contribute to the definition of populism as a political communication style and to the identification of the populist's stylistic features and elements as a mode of persuasive communication that has been recently adopted by leaders of mainstream political parties. This research intends to explore how to measure the employment of the populist style of political communication. This research investigated to what extent this style was adopted by Hilary Clinton and David Cameron in their latest campaign discourses in 2016; comparing their speeches before and after the rise of the populist zeitgeist. 
Two main theories were applied the rational choice theory which describes how political actors apply a behavioral rule in by deciding what tools or techniques are used to reach to specific goals and purposes such as winning votes in elections and the theory of behavioral contagion explains why politicians would act in a populistic style consciously or even unconsciously.
Quantitative content analysis was carried out to measure the intensity of populist communication. A purposive sampling was conducted in which speeches were selected five months before the voting day; one speech per month and speeches that contained controversial themes were selected for the sake of covering a diversity of issues and topics that are of people's concerns.  In total twenty speeches were analyzed, ten for Clinton (five from USPE in 2008 and another five from 2016). As for Cameron's speeches five were selected from GE in 2010 and five other speeches from 2016 Brexit referendum elections. 
Both candidates have been influenced into adopting the populist communication style. The thesis proved that there is a positive correlation between the successful electoral performance of populist actors and the adoption of the populist style of communication by mainstream politicians in their campaign discourses.