Pascal Merz

• This dissertation examines when and how social media influencers become politically relevant communicators. It distinguishes between influencers who primarily emerge from lifestyle contexts and only sometimes address politics, and those who consistently explain and comment on public affairs. The central argument is that these actors do not become politically consequential in the same way. While some may depend more strongly on relationship-based bonds, others depend more strongly on visible guidance and explanation. To capture these dynamics, the dissertation conceptualizes influencers as communicators who combine personal proximity with functions of orientation and guidance. It also asks a broader normative question: not only whether audiences see influencers as politically relevant, but also whether this relevance is justified in epistemic terms. Across three manuscripts, the dissertation develops a cumulative account of these dynamics. The first shows that political relevance is not evenly distributed, but concentrated especially among politically engaged social media users. The second shows that factual learning depends primarily on the substance of the content, whereas feeling informed is shaped not only by content but also by who delivers it. The third shows that participation-related effects depend more strongly on relational closeness, with parasocial relationships acting as an important moderator. Taken together, the dissertation shows that influencers matter politically in different ways for different audiences and outcomes. Its contribution lies in explaining these differences systematically. That is, by distinguishing influencer types, by outlining that relational closeness and opinion leadership could matter differently across outcomes, and by embedding these findings in a broader framework that considers not just political influence, but also the quality of that influence.