The paper presents the results of the empirical study devoted to mapping and measuring the aggregated political positions – viewed as a specific form of discursive public opinion – expressed by ordinary citizens on a discussion forum on the Russian internet. The study is considered as part of the broader inquiry into the field of online deliberations. New evidence is discussed in this regard by deepening the empirical side of claim making and validation through studying agreements and disagreements among online discussants using Jurgen Habermas’ notion of validity claims to normative rightness. The claim-based approach has helped reveal, firstly, how participants problematize issues of public importance and what these issues are, and, secondly, which intersubjective solidarities (groups) participants form around these issues. The paper concludes by considering both the epistemic and pragmatic aspects of such results for better understanding the participatory value of public discussions online from a perspective of discursive sociology and public trust building.