Inside Trump's antifa tweet

As recently as Saturday night, senior administration officials told me that the designation of a violent cohort of far-left activists, antifa, as a terrorist organization was not being seriously discussed at the White House. But that was Saturday.

Behind the scenes: The situation changed dramatically a few hours later, after prominent conservative allies of the president, such as his friend media commentator Dan Bongino, publicly urged a tough response against people associated with antifa (short for "anti-fascist").

• A senior White House official told me that on Sunday morning, President Trump discussed the move with White House Chief of Staff Mark Meadows and Attorney General Bill Barr.
• Then, at 12:23pm, Trump tweeted: "The United States of America will be designating ANTIFA as a Terrorist Organization."

Yes, but: There currently is no law under which Trump could formally designate antifa, a loosely defined and domestic movement, as a terrorist organization. Only the State Department can designate foreign groups as terrorist organizations.

• Mark Bray, author of "Antifa: The Anti-Fascist Handbook," wrote of Trump's tweet: "To explain a little: it's like calling bird-watching an organization. Yes, there are bird-watching organizations as there are Antifa organizations but neither bird-watching nor antifa is an organization."

About an hour after Trump's tweet, Barr said in a statement that antifa protesters were engaged in domestic terrorism.

• "To identify criminal organizers and instigators, and to coordinate federal resources with our state and local partners, federal law enforcement is using our existing network of 56 regional FBI Joint Terrorism Task Forces."
• "The violence instigated and carried out by Antifa and other similar groups in connection with the rioting is domestic terrorism and will be treated accordingly."

Go deeper: DOJ to treat antifa involvement in protests as domestic terrorism