If it is done by popular vote, I suppose they will have to move. I agree, Mass. could do us a favor IF they secede :)
They almost did, look up info on the Hartford Convention. The principle nullification was accepted by those Yankees at least, though as one would expect it was over their objection to a war.
Nope, rights protected under the constitution cannot be taken away by popular vote. You can't censor a newspaper or outlaw a religion just because the majority votes to do so.