Martial law cannot be declared for a mob invading a law abiding citizen that is protecting his and his families own life and property, it would be a clear case in any reasonable court of law of justifiable homicide (case closed handled by local authorities, not the president of the United States).
No the imposition of martial law would require a local city or county or state or group of states to armed rebellion against the upper authorities and each case would have to be determined by the proper county state or then last federal authorities.
I am 58 years old and martial law has never been imposed and I hear of it often when you have a crappy president but I think as far as I can tell Lincoln was the only one to use such federal powers, but in the middle of a war what does that matter, the states were fighting the union so in that case martial law didn;t really matter that much then did it!
