Go after Antifa itself as a criminal/terrorist organization which promotes violence. Force a judge to come up with reasons to turn you down...and then appeal to the next level. The suit should be in the federal courts, given that Antifa is a multi-state organization.
You are assuming there is anyone, anywhere in DOJ, that has a pair. Afraid not. There are all castrated like Sessions.
No leftist has to fear Trump’s DOJ.