> Politics has in recent decades entered an era of intense polarization.
Explanations have implicated digital media, with the so-called echo
chamber remaining a dominant causal hypothesis despite growing challenge
by empirical evidence. This paper suggests that this mounting evidence
provides not only reason to reject the echo chamber hypothesis but also
the foundation for an alternative causal mechanism. To propose such a
mechanism, the paper draws on the literatures on affective polarization,
digital media, and opinion dynamics. From the affective polarization
literature, we follow the move from seeing polarization as diverging
issue positions to rooted in sorting: an alignment of differences which
is effectively dividing the electorate into two increasingly homogeneous
megaparties. To explain the rise in sorting, the paper draws on opinion
dynamics and digital media research to present a model which
essentially turns the echo chamber on its head: it is not isolation from
opposing views that drives polarization but precisely the fact that
digital media bring us to interact outside our local bubble. When
individuals interact locally, the outcome is a stable plural patchwork
of cross-cutting conflicts. By encouraging nonlocal interaction, digital
media drive an alignment of conflicts along partisan lines, thus
effacing the counterbalancing effects of local heterogeneity. The result
is polarization, even if individual interaction leads to convergence.
The model thus suggests that digital media polarize through partisan
sorting, creating a maelstrom in which more and more identities,
beliefs, and cultural preferences become drawn into an all-encompassing
societal division.