There’s a reason you separate military and the police. One fights the enemies of the state, the other serves and protects the people. When the military becomes both, then the enemies of the state tend to become the people.
What quiz, you ask? Why this one: The General Geek Knowledge Test
Allow me to refer you to the now defunct “Posse Comitatus Act of 1878”. The above explains why we had Posse Comitatus in the first place. But it’s defunct thanks to a provision of the “John Warner National Defense Authorization Act for Fiscal Year 2007”, specifically “SEC. 1076. USE OF THE ARMED FORCES IN MAJOR PUBLIC EMERGENCIES.” The President was granted the authority to
[…] employ the armed forces, including the National Guard in Federal service, to–
`(A) restore public order and enforce the laws of the United States when, as a result of a natural disaster, epidemic, or other serious public health emergency, terrorist attack or incident, or other condition in any State or possession of the United States […]