It sort of is, but I think it is also distinct from your average ad hominem and widespread enough to deserve it's own name. You don't call someone "tankie", "woke", "SJW" and the likes the same way nor for the same reasons you would call someone an idiot or a pig nor does it have the same kind of implications. It's not just any kind of common name calling, it imply the target is an active part of some nebulous group that is inherently assumed to be a threat to some "fundamental value of our society", it is specificaly reserved for peoples who are a threat (or at least perceved threat) to the status quo.