The word 'antifa' is an adjective. Like "anti-government."
It is can apply to non-violent activism, not just militant/revolutionary groups.
Even is they are non-violent.
Even if they aren't part of some hardcore leftist group.
@ACLU or @peoplefor could be labeled as "terrorists."
The "Patriot mov't" is not a single unified organization, just like the antifa movement.
A patriot militia in New Jersey has nothing to do with one in Washington State.