Antifa doesn't need to be a political organization to be a terrorist organization.
you're right, it needs to be an organization in order to be a terrorist organization. legally, antifa is not an organization. so forget your 'in context it is' bullstuff because this is a country governed by law not the flimsy ass property of equality bullstuff you pretend is 'logic'
if you want to present state-certified documents, straight out of the town hall of whatever the forget chapter is nearest to you, stating that all of antifa and its global connections in france, germany, italy, switzerland, and wherever, is a legal organization with irs tax exemption, licenses and permits that certify it as an organization, you'll have maybe an ounce of credibility in the argument.
until then 2 things are true: a) it's not an organization, and b) you're full of stuff. so take your entirely unconstitutional censorship scheme over to the middle east and pitch it there