More on this later. I've been awake 23 hours and must must crash.
Ordinarily I'd say "yes and hell yes" for a million different reasons, not the least among which is the training which you will find useful in the dark times ahead, and the experience which will put you on a solid foundation for when hot lead starts flying around the US.
Right now though.... things are geting bad. real bad. Disobeying an order you decide is unlawful (but they decide otherwise) could buy you a hell of a lot more than a little 'humiliation,' it could land you in the brig, or worse. I'm divided yea or nay on this one. The USMC (contrary to popular opinion) is probably your safest bet of all the services in the way of refusing to do something that is obviously illegal and not getting in trouble for it. You wouldn't think so from the outside looking in, but Marines tend to be WAY more independant minded than soldiers, sailors, and airmen.
Of the 4 regular branches, you will find more respect for the Constitution in the Marines than anywhere else. There are probably more people of the "Ron Paul mindset" in the Marines than any other branch -- and we are the smallest branch.
Lits of reasons to say yes, lots of reasons to say no.
I gotta hit the sack, more on this later.