You're right I was about to change my post to be less absolute however I don't think we are at the point of Civil War yet. It should be a last resort. I prefer the tactics of non-violence.
From what I understand, the point of Antifa is that it's much easier to stop fascism in the early stages, before it takes over the country. If it gets to the point of civil war, then it's already a massive failure, not a starting point for violence.