Social networks are generally regarded as channels through which parliamentarians establish direct contact with the public. However, do they engage in these activities personally or rather delegate them to their parliamentary assistants? This study examines the intermediary relationship between parliamentarians and the public (henceforth PAs)—seeking to understand their role in contemporary, political communications. While numerous studies have looked at types of parliamentarian contact with the public, PAs have received little scholarly attention. Adopting a comparative perspective, this study will suggest a theoretical model of the MP/PA social media work relationship, creating a new questionnaire for PAs in the US House of Representatives, German Bundestag, and Israeli Knesset, exploring whether level of parliamentarians’ involvement in social networking is influenced by working within different electoral systems: representatives elected directly (the United States), mixed (Germany), and indirectly (Israel). The study investigates the level of parliamentarians’ engagement with social media communication according to a four-category model.