Yes, Trump really has authority to use military force at the border
by Tom Rogan
| November 21, 2018 02:39 PM
The president has the authority to use military forces to defend our country's territory. The president also has authority, by law and by precedence, to use military forces to support civil authorities in preserving the peace.
I note this in light of Tara Copp's report for the Military Times on Wednesday, which explains that the White House has authorized U.S. military personnel stationed at the U.S.-Mexican border to use force in support of Border Patrol and law enforcement authorities. This use of force entails actions that the "Secretary of Defense determines are reasonably necessary," including "a show or use of force (including lethal force, where necessary), crowd control, temporary detention, and cursory search."
That authorization has some commentators enraged. They claim President Trump is about to shred federal law relating to the Posse Comitatus Act, which prevents the military's use in most civilian law enforcement matters.
https://www.washingtonexaminer.com/opinion/yes-trump-really-has-authority-to-use-military-force-at-the-border