It is certainly an open question whether Obamacare is constitutional and hopefully those opposed will come up with a GOOD case to take to court. A bad case would be a disaster.
Arizona’s law is not in CONFLICT with federal law but actually suppliments it so the “Supremacy Clause” does not appear to truly apply contrary to de jedge’s allegation.
But the constitutionality of secession is not in question and never was if the greatest of our founders thoughts are considered.
I think we pick and choose what we are “allowed” by the federal government to do and what we are not allowed to do. Sorry. I don’t see any difference. Of course its for the betterment of the nation to forbid the southern states to secede. The southern states through their conservative voting somewhat keeps the feds in check. The sparsely populated western states (Bless them) couldn’t do it on their own. In 2008, the usually conservative states deviated somewhat and voila! We got Obama.