Sentiment and topic analysis are commonmethods used for social media monitoring.Essentially, these methods answers questionssuch as, “what is being talked about, regardingX”, and “what do people feel, regarding X”.In this paper, we investigate another venue forsocial media monitoring, namely issue ownership and agenda setting, which are conceptsfrom political science that have been used toexplain voter choice and electoral outcomes.We argue that issue alignment and agenda setting can be seen as a kind of semantic sourcesimilarity of the kind “how similar is sourceA to issue owner P, when talking about issue X”, and as such can be measured usingword/document embedding techniques. Wepresent work in progress towards measuringthat kind of conditioned similarity, and introduce a new notion of similarity for predictive embeddings. We then test this methodby measuring the similarity between politically aligned media and political pparties, conditioned on bloc-specific issues.