Several times recently, President Trump has suggested that the loosely organized Antifa (Anti-Fascist Action) groups that have shown a proclivity toward violence in a number of cities nationwide should be designated a terrorist organization (see, e.g., here and here).
There is little doubt that Antifa meets the threshold for definition of terrorist activity, in that it uses violence and intimidation to achieve its political goals, however vague and unfocused they may be. And there is no small irony in that when considering the so-called aims and name of the organization, because Antifa's tactics closely resemble the kind of unbridled rage and violence unleashed by fascists during Kristallnacht.
But what would such a designation mean, and what are the implications?
That's a difficult question to answer because, while the USA Patriot Act defined "domestic terrorism", there is no provision in federal law for designation of domestic terrorist organizations. The relevant law pertains solely to international terrorist groups, and can be found at Section 219 of the Immigration and Nationality Act, 8 U.S.C. Section 1189. Designation of foreign groups carries with it implications in both the criminal and civil removal laws; there are even financial implications since a designated organization's assets may be frozen. No such implications pertain to domestic groups since they simply can't be designated. What's more, designation under Section 219 only takes place after a consultative process involving a multitude of departments and agencies: Homeland Security, State, Treasury, Justice, the CIA, DIA, and FBI, at a minimum.
It's doubtful that the federal government could reasonably meet the burden of describing Antifa as an international terrorist group, even though it — or its mirror image — has made itself known in some foreign cities. In fact Wikipedia tells us that Antifa was originally established in the United Kingdom.
Perhaps when the president first made the suggestion, he was unaware that the statute limits itself to international, and not domestic, organizations. Given the limitations described, would there be value in such a "declaration" and how might it be achieved? There might be symbolic value, and if issued as a presidential directive, might serve to direct the FBI and other law enforcement organizations to place a priority on investigation of the group's unlawful activities.
What is fairly evident, though, is that the Immigration and Nationality Act will not serve to further the president's expressed intent where this group is concerned.