There is no such thing as a 'domestic terrorist organization'. It is illegal to classify any domestic organization as terrorist. That's why the KKK isn't one, and it's why Antifa isn't one either, Trump's blustering about it notwithstanding.
Even though being antifa is simply being against fascism.
Fortunately our legal system doesn't operate on the basis of Trump's tweets.
Equating the antifa group and it's loose "members" with just an anti-ideology is a cop-out that isn't helpful to differentiating a desirable mindset (anti-fascism) with the undesirable tactics that many "members" of Antifa use.
https://www.factcheck.org/2020/06/trump-cant-designate-antif...