The Rules of Engagement: How the Public Interacts With Elected Officials on Social Media and What Can Be Learned From Their Interactions

Political science research has largely overlooked the role of user engagements when studying communications on social media. Whether this feedback influences the communications of elites and whether anything can be learned from this data remains unknown. This dissertation presents some of the first evidence that social engagement data can be used to study political communications on social media and, in particular, how elites use the platform to broadcast their messages. The dissertation includes two empirical studies and a methodological chapter focused around the study of social engagements. The first study examines the feedback dynamics between legislators\u27 communications and the social engagements they receive. It finds no evidence that legislators respond to the user engagements they receive on social media, but that legislators respond to one another and are able to steer the issue attention of the virtual public. The second study develops and validates a technique for measuring the ideological content within social media messages based on their network of social engagements. It pairs a network-based measure of ideology on social media with an on-line data reduction technique to produce a big data measurement strategy that is unconstrained by researchers\u27 hardware limitations. The method is applied to a set of more than 840,000 Facebook posts authored by elected officials, and reveals systematic differences in their electronic homestyle. The third study of the dissertation applies the measurement technique detailed in Chapter 3 towards understanding the ideological dynamics of campaign communications. It finds that candidates running in competitive elections moderate the ideological extremity of their communications after winning their primary election, but the degree of moderation is meager compared to the moderating trends exhibited by all candidates across the entire election. This social-engagement-based measure of ideology offers an empirical insight into a longstanding question in political science surrounding the phenomenon of post-primary moderation. In total, this dissertation justifies a case for including user engagements in future empirical investigations, and provides researchers with a novel tool for exploring politicians\u27 social media communications