  This article analyses public debate on Twitter via network representations of
retweets and replies. We argue that tweets observable on Twitter have both a
direct and mediated effect on the perception of public opinion. Through the
interplay of the two networks, it is possible to identify potentially
misleading representations of public opinion on the platform. The method is
employed to observe public debate about two events: The Saxon state elections
and violent riots in the city of Leipzig in 2019. We show that in both cases,
(i) different opinion groups exhibit different propensities to get involved in
debate, and therefore have unequal impact on public opinion. Users retweeting
far-right parties and politicians are significantly more active, hence their
positions are disproportionately visible. (ii) Said users act significantly
more confrontational in the sense that they reply mostly to users from
different groups, while the contrary is not the case.
