We're not talking about criticizing antifa, but calling it a 1.) terrorist 2.) organization.
> Many of those proclaiming to be antifa have committed acts of violence
And many people who criticize antifa are fascists, but neither of these facts are an argument for the above.
> You can be completely against fascism but disagree with the violent tendencies of many who associate themselves with the antifa label.
And how do you get from there to "declaring antifa a terrorist organization"? You have done nothing to explain that leap.
> If the former, you also know that "antifa" is short for "antifascist" and your clear designation of that as an enemy is also clear signaling that you're in for fascism.
In particular, I'm responding to "designation of that as an enemy" which is not the same as calling it a terrorist organization. People who oppose fascism and violence may call antifa an enemy for the violence committed and espoused in antifa's name. If someone commits violence against me, or any other innocent people I call allies, then they are certainly my enemy, whether I agree with their ideology or not. You can agree with something in principle (be anti-fascist) but not support particular methods (violence).
> People who oppose fascism and violence may call antifa an enemy for the violence committed and espoused in antifa's name.
Great, but can they either a.) bring that up on their own, or at least b.) pay attention to the context they attach this complaint to?
Unless you want to make the case for labeling antifa a terrorist organization, what you may "call enemy" or "disagree with" some or all aspects of what you may or may not consider antifa is simply not relevant. The strong ["antifa is a terrorist organization"] has been made, it's on the table; and you're defending an infinitely weaker claim nobody even hinted at disagreeing with, apropos nothing.
Without a clear argument as to why antifa is a.) an organization and b.) as such terrorist, I don't think you can. It's like saying "Jews start all wars, I'm against antisemitism".
I'm not interested in debating whether or not antifa is a terrorist organization, and doing so is not necessary to support the point I am making. All I am saying is that some people may have a different understanding of antifa, and believe antifa is a terrorist organization not for its stance against fascism, but for its violent methods. These same people may be completely against fascism but oppose those labeled antifa for the baggage associated with such a label.
The root issue is the implication that being antifa is nothing more than being against fascism. If that were true, then I agree with you. But it's not. The antifa label has become associated with political violence (just read the Wikipedia article). To most people, it no longer means simply being against fascism, but also has associations to antifa's violent methods. Many of the debates about antifa, and I think also this one, stem from the fact that people have different understandings of what antifa actually means. I think it is deceptive to pretend that antifa means nothing more than being against fascism, in the current political context. Perhaps it meant that in the past, but that is not the common understanding anymore.