sworn duty to defend the US Constitution against enemies both foreign and domestic. It is their duty to ignore orders from the POTUS that are in violation of the Constitution. Their obedience to obey orders from the Commander-in-Chief is second to the above. It is one of the checks and balances in place to the POTUS grabbing power s/he is not entitled to.

Can you say JAG? And where are they?

I never thought I would live to see the day when we would have the occupation of our own cities by our own military. They are NOT a police force. They are NOT trained to preform police work.