  Political expression through social media has already taken root as a form of
political participation. Meanwhile, democracy seems to be facing an epidemic of
incivility on social media platforms. With this background, online political
incivility has recently become a growing concern in the field of political
communication studies. However, it is less clear how a government's performance
is linked with people's uncivil political expression on social media;
investigating the existence of performance evaluation behavior through social
media expression seems to be important, as it is a new form of
non-institutionalized political participation. To fill this gap in the
literature, the present study hypothesizes that when government performance
worsens, people become frustrated and send uncivil messages to the government
via social media. To test this hypothesis, the present study collected over 8
million posts on X/Twitter directed at US state governors and classified them
as uncivil or not, using a neural network-based machine learning method, and
examined the impact of worsening state-level COVID-19 cases on the number of
uncivil posts directed at state governors. The results of the statistical
analyses showed that increases in state-level COVID-19 cases led to a
significantly higher number of uncivil posts against state governors. Finally,
the present study discusses the implications of the findings from two
perspectives: non-institutionalized political participation and the importance
of elections in democracies.
