Like surveys, Twitter is a new means of observing public opinion, and even a predictor of election results according to some authors, but the messages posted on the network are often not associated with the socioeconomic characteristics of their authors. Researchers are therefore limited to studying the network’s opinion as a whole, without separating the various social subgroups involved in the debate (students and professionals, leftwing and right-wing activists, etc.). In order to overcome this limitation, we created a panel of 1,228 political twitterers whose socio-demographic characteristics we identified through a questionnaire. The analysis reveals that the number of political tweets posted by the panel is strongly determined by the sociological and political makeup (age, profession, level of interest in politics) of twitterers, but also by the degree of politicization of the news.