Date of Award


Degree Type

Restricted to Claremont Colleges Dissertation

Degree Name

Political Science, PhD


School of Social Science, Politics, and Evaluation

Dissertation or Thesis Committee Member

Melissa Rogers

Dissertation or Thesis Committee Member

Tyler Reny

Dissertation or Thesis Committee Member

Carlos Algara

Terms of Use & License Information

Terms of Use for work posted in Scholarship@Claremont.

Rights Information

© 2024 Shawn G. Matiossian


Communication, Economics, Media, Political Science, Politics, Social Media

Subject Categories

Communication Technology and New Media | Political Science


This dissertation examines the landscape of political communication and its implications on democracy, exploring the transition from traditional media to the digital age and its subsequent effects on political ideologies and polarization. The first paper discusses the evolution of political communication across five distinct eras, beginning with stump speeches and partisan newspapers and building up to the current era dominated by social media and smartphones. This historical overview reveals how technological advancements have revolutionized how politicians engage with voters, highlighting the transformation of media platforms and their significant impact on democratic processes. Lastly, the paper discusses the influence of media on shaping political polarization, emotional engagement, and informed participation in the political sphere. The second paper focuses on Twitter's role in shaping political discourse, examining the content and emotional language used by U.S. Senators in their tweets. By analyzing tweets from selected Senators across the ideological spectrum, the study looks at patterns in the frequency of topics, the attack of out-party members, and the use of emotions in communications. The findings suggest a correlation between ideological extremity and emotionally charged language on Twitter. Finally, the third paper examines the ideological shift caused by social media in American politics. Using a nationally benchmarked public opinion survey, I explore the relationship between social media usage and ideological extremism and illustrate how exposure to ideologically extreme content on social media platforms influences self-reported ideology and policy support among Americans. The provides a comprehensive quantitative analysis of these trends and discusses their broader implications for national politics. Together, this dissertation offers a comprehensive illustration of the transition in political communication and its effects on the political landscape, ideology, and engagement in the age of digital media.