That's a great and concise way to describe what those people have done, or are trying to do. I've seen it on several old forums or games, like the Something Awful Goons invading Eve Online with the stated aim of ruining the game for everyone else.
It's this weird immature streak of "everyone pay attention to me" that these hateful vandals thrive upon. They have to be the only ones making noise, and everyone must listen to that noise. If things don't happen exactly like they want, they throw fits, threaten, and whine as a group so much that people give in just to shut them up. And since it's just attention that is being sought, any actions are valid, good or bad. Appeals to admins/moderators, spamming, arguing in bad faith, harassing others, defacing the site or simply breaking as much as they can. How that attention seeking validates these people, I have no idea.
/r/politics is only left-leaning because of how heavily skewed right american politics is. Most of their opinions are centrist at best. Their obsession with trump is a bit annoying, but it's only annoying, not actively harmful.
Of course I am not referring to the worst stuff on that subreddit, there is shit there but if a sizeable part of the population has views like this is banning it really fair? I worry that banning public speech by a large segment of the population fractures the population that makes things even worse. And once fully separate it leads to even more echo chambering and divergent realities and more problems, not less.
But again that is assuming it is genuine and not trolls or foreign interference and it is truly sizable and not fringe.