Finally, I will note PSOL has a point too (which ties in very nicely with YE's argument about polarization). If you think about it, Atlas hasn't really become more left wing compared to say, 2012; when there were lots more maroon avatars or their predecessors, with far left rethoric and what not. It's not like Atlas is now less ideologically diverse because we have a ton of rose Twitter socialists, instead Atlas just has a ton of partisan generic Democrats (I often talk about the "red avatar blob" which is true) The modern Atlas poster isn't really more left wing, it is just way more partisanly Democratic and pro-establishment. I can think of very few left wing anti-Democratic (or skeptical of Democrats) posters (PSOL indeed being the highest profile one, a couple of maroon avatars, but that is it).
This isn't accurate. This forum has never been a sympathetic place for the hard left, for the straightforward reason that nothing is more electoralist than discussing election maps. Beyond that, Democrats on this forum have shifted in similar ways to young Democrats in general in this country. Maroon avatars didn't exist a decade ago and there was no perceived need for them. Sentiment among left-of-center posters was universally effusively supportive of Barack Obama during the 2012 campaign. The Bernie Sanders movement dragged people to the left here as it did everywhere.