I know mine is probably not the popular opinion on this...but IMHO I think it should still be up to the individual states to set their policy on concealed carry...so long as it doesn't violate the 2nd Amendment or subvert it in any way.
The problem is this: I am fully licensed to carry concealed (or openly) in my home state of New Hampshire. I live 30 miles from Massachusetts, which does not recognize NH firearms licenses, and which maintains draconian gun laws, besides.
But any time I have to drive over the border - for example, to visit my father-in-law on Cape Cod - I have to make certain to remove the pistol I carry in my car's glove box before I leave. Were I to be stopped and the pistol discovered, I would be in a world of trouble, facing felony charges, financial ruin, and
likely jail time - all for an action that is perfectly legal 30 miles away, making a felon of an otherwise law-abiding citizen.
Sorry, but that is insane and I might well argue, inherently violative of Article IV, Section 1 of the Constitution, the 14th Amendment and also Federal equal protection statutes.