Military police work may not be feasible.

If Trump uses the military for police work, that is rounding up illegal immigrants. That is unconstitutional and violates posse comitatus. It is grounds for impeachment. President establishes that it's marginal to use them to defend the borders themselves but if it intrudes on non-border areas using the army for police work is a direct violation of established constitutional law.

It's also a really bad idea because armies are trained to kill people not uphold the law. For a long time our police forces have been making the mistake of hiring ex-military people which is very bad idea because the functions of enforcing the law and keeping the peace are anathema to the kinds of things that you need to do when you are suppressing a population, or invading and controlling an area.

Rand Paul had some interesting things to say earlier today. I'm not the biggest Rand Paul fan but I think he appreciates the importance of not militarizing police forces. I'll link below.

If he actually goes ahead and starts deploying military in the cities I will be at protests and I will tell every soldier I see in cities doing police work that they are following an unlawful order. Yes this is a kind of maneuver that can be followed by expansion and abuse of power leading further to a dictatorship. I think there is a fairly high chance that this is the usual random trumpian bluster but in case it's not. I want to make my position clear and I hope most of you agree with me.