Wiktionary
groupuscule
n. A small political group, especially of an extremist faction.
Usage examples of "groupuscule".
Political motives -- both parties were well known for their radical views -- could not be discounted, though such was the muddiness of the water in the far-left groupuscules they frequented that it would be hard ever to get a clear picture of what such motives might have been.
These three were obviously some variety of neo-Nazi / Christian Identity / Aryan Brotherhood types, one of the groupuscules that had set up redoubts in northern Idaho through the eighties and nineties as part of the survivalist wave - or the scum on the wave, to be more descriptive.