President Donald Trump tweeted Sunday that the United States will designate Antifa as a terrorist organization, even though the US government has no existing legal authority to label a wholly domestic group in the manner it currently designates foreign terrorist organizations. US law allows terrorist designations for foreign groups since belonging to those groups doesn't enjoy the same protections. That has made it difficult for US law enforcement to deal with violence from members of groups that label themselves as Antifa. In response to the President's tweet, ACLU National Security Project Director Hina Shamsi said there is "no legal authority for designating a domestic group" as a terrorist organization. There is no legal authority for designating a domestic group.