Trump wants to declare antifa a terrorist group but I don’t think it’s been done yet. He doesn’t get to declare that. It’s up to DHS I believe. So no, no one has been arrested for supporting antifa the terrorist group yet because there’s no such thing yet.
Video breaks down how Antifa works at the protests and turns them violent
https://twitter.com/_Crypto_Maniac_/status/1269041655098859527