evernon

That describes exactly what is happening. An individual's nuanced stance and well reasoned argument doesn't matter so much as their use of a hashtag does. Anyone on the fence is fraternizing with the enemy. The sides are ill-defined, but certainly delimited by what the self-ascribed gatekeepers at the top of the social jenga tower consider personally "deplorable", through blacklisting and social pressure.

This does explain why platforms like Facebook and Google have arrived at the sad inevitability of filter bubbling.