Brexit on Twitter: Unraveling the Dynamics of Polarization Over Time

This paper uses a mixed-methods approach to examine the evolving dynamics of polarization amongst Twitter users who discussed the UK's withdrawal from the EU from February 2016 to February 2020. Unlike previous research that mainly focused on specific time-frames, this study investigates the longitudinal changes in the network structure and the affective polarization of Twitter users before and after the referendum, reflecting a critical time of intense political debate about the UK's future in the EU. We challenge the conventional belief that Leave supporters were more polarized than Remain supporters over time and show that, to some degree, the opposite was true after the referendum. We also provide empirical evidence of increasing out-group hostility and ideological extremity among both groups over time.