In 1995, Blumler and Gurevitch identified the crisis of public communication hindering deliberative democracy in the televised age by examining the Press-Politics-Public (3P) nexus. This televised age, characterized by the competitive struggle between political and media institutions, was further contextualized as the third age of political communication (Blumler, J. G., & Kavanagh, D., Political communication 16:209−230, 1999). As digital media technologies have spawned new opportunities for the public to actively engage in political communication as message creators and disseminators, the fourth age of political communication has emerged and matured. In celebration of Jay Blumler’s intellectual legacy, this chapter examines how the 3P nexus functions in the fourth age of political communication. Specifically, we review four phases in the fourth age of political communication that reflect the evolution of digital technologies: the search stage, social media stage, citizen journalism stage, and multi-modal stage. Next, we evaluate the ‘vulnerable potential’ of digital media (Coleman, S., & Blumler, J. G., The Internet and democratic citizenship: Theory, practice and policy, 2009), focusing on its democratic capabilities to enable active citizenship and its vulnerabilities to erode democracy. Lastly, we demonstrate how dysfunctions within the 3P nexus exacerbate the crisis of public communication in the fourth age of political communication.