How Centralized is Party Communication on Social Media?

Social media has become an indispensable tool for politicians, allowing them to bypass traditional media and party filters to directly communicate with voters. This presents both opportunities and challenges for political parties. On the one hand, politicians can personalize their message to resonate with local constituents. On the other, parties risk appearing disjointed with potential electoral consequences when they fail to present a clear message. To understand whether parties are able to ensure a coherent message in the new media environments, this study examines parties' retweet networks on Twitter in Germany, the Netherlands, and the United Kingdom between 2017 and 2021. We argue that party communication remains predominantly hierarchical, particularly in larger parties. Party elites and official party accounts serve as focal points, creating content that gets disseminated by regular MPs. Unlike party elites, official party accounts play a role in amplifying regular MPs’ messages to a wider audience. We employ Exponential Random Graph Models to assess the structure of parties’ online communication networks, analyzing nearly 400,000 retweets. The results confirm the core predictions of our theory.