Here's my opinion, and I have some background to strengthen it. Police agencies, federal or state, are made of people who will do their jobs. They will always do their jobs. It's in their makeup to put down disorder.
The huge difference between a police officer and a brick layer is that the brick layer is in it for the money, and that's all. He might like to lay bricks, but he wouldn't do it for free. A police officer puts himself in danger not for the money. Sure, he gets paid, and he grumbles, but his reason for working is that he believes in his heart that he is part of the solution. If a particular act is illegal, he strives to stop it, to suppress those breaking the law. To bring them to what he sees as justice. THAT is why he goes to work.
Maybe there are incidents where the police refused to do what they were sworn to do, but in such a major event as marshall law being declared, the blue meanies will be in your face to make certain you comply.
I mean to dispute someone's statement above that a particular agency "are snakes in the grass." Be thankful you don't have to do what they do, and be certain they will be your friends when those fighting marshal law attempt to disobey. And they are just one agency. The combined strength of all agencies would be against violators.
I'm not saying we ought to blindly obey government restrictions and requirements, I'm just saying that we most certainly will. We can play with what authority the locals and the feds have over us, who can do what to enforce what, but such thinking leads to disorder that can't stand. The fallout from civil disorder always quickly descends into death and desperation for the people who start it or join it. The fact that we could not survive the lack of goods and services is just a small item of importance when it comes to fighting the system.
Let's look at one little gov't act that we would detest. Let's say the liberals finally get what they want, and a law is passed that all firearms are illegal to possess. It is declared a felony. We can use another scenario, but I like to think this one hits home a little harder. Okay, you've got 30 days to turn in your guns. After that, they come and get them using "whatever force neccessary," which is a phrase well known to any cop. Lines outside the turn-in locations are long and full of hate and resentment. But the law is the law.
Okay, the 30 days has passed. Now you are a felon if you have a gun. You had your chance to comply, and you did not. Now, if your caught, you go to prison. Firstly, without boasting, who among you would have kept your guns? Let's assume you were one. At 4am Christmas morning, the feds use a battering ram or a flash-bang device to come in your home to get your 9mm. Resistance is met with resistance. However that scene plays out, you lose.
What we can tell ourselves inside minds diseased by fantasy, is that forces of revolution would have already joined together, and their would be civil uprising strong enough to oppose the federal gov't, who has the might of the military. We could oppose them with our illegal small arms. Right.
The other fantasy we might rely on is that the agencies would revolt against the new law, and there'd be no one to come after you. My first remarks on this post should make us understand that will never happen. I was a cop a long time. I never backed away from enforcing a law I didn't like. No officer I ever knew gave his credentials away so easily. We here about corruption by police in big cities, and I know it's there, but it's limited to the point that it has and never will stop enforcement.
I'm saying it will take more than marshall law or anyother kind of gov't mandate to bring us to arms against our own nation. No, I don't ignore history when I say that. But today's society is nothing like it was in those times. And even with the combined strength of minds and arms, that issue was lost for the people who fought to keep it. It can't be done that way. Not that I have a better way.