President Donald Trump’s National Guard directive was issued as he touts his efforts to assert control over D.C. and muses about deploying troops to other major U.S. cities.

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.