The US reserve military force is activated for federal missions and state emergencies, from disasters to civil unrest.

If Trump sends the National Guard into cities without the consent of governors, state leaders would be able to file court challenges, as California Governor Gavin Newsom did to block Trump from federalizing the National Guard to quell protests and riots over his immigration policy in Los Angeles earlier this summer, Banks said.

President Trump said he needed to send in the Guard to secure the nation’s capital. But on Jan. 6, 2021 — the most lawless day in recent Washington history — he had a very different reaction.