> because that's actually not a thing he's legally able to do
This has not helped a whole lot over the last 3.5 years. When something is illegal, but no one is willing to enforce it, the legality doesn't have much impact.
This president, and the current administration, has demonstrated little regard for legality, and a clear intention to grab as much power as they can.
According to Wikipedia (maybe not optimal source), via the PATRIOT Act, groups can be designated as domestic terrorists.
I don’t know anything about this topic. Can you expand why you said that there is no “...legal authority to designate a domestic organization as a terrorist group”.
I’m no asking about Antifa specifically but generally.
The very first sentence of the Wikipedia article you linked to has your answer: "Domestic terrorism in the United States consists of incidents confirmed as terrorist acts."
incidents confirmed as terrorist acts. The PATRIOT act defines acts of terrorism.
It's on a case-by-case basis. It is not possible to take a domestic organization and designate it wholesale as terrorists.
The page also explains that there is no federal criminal offense that is "domestic terrorism".