I'm pretty certain there is already enough precedent that the 10th Amendment (States Rights) has already been pretty much gutted. It's a paper tiger within the Bill of Rights. However, I myself don't really like the idea of a single federal permit carry law, since it would be too easy to repeal. IMHO interstate compacts (agreements between states to recognize the other's ccw permits - reciprocity) are the way to go since those will have to be dismantled locally and one at a time. But it might be nice for the FEDS to offer a national level reciprocity blanket for all states who have any form of permit system to recognize other states permits like driver's licenses are recognized nationwide. Most states have permit's available but they may be severely restricted. New York has one, so does New Jersey and California. Never mind that those states are examples of gun control Mecca, they still have ancient permit regs on the books. That's the benefit of federal legislation.