Thank you for the clarification on state's powers.
I'm not sure if it's important that a state have a pre-existing law on the books that a new federal law would interfere with or infringe upon.
Since today we have several states with state laws that govern what types or models of firearms are available for sale to the public, it seems that a federal ban would infringe on that state's power.
Can any state bring forward a case claiming infringment on states' powers, even if the state filing the case doesn't specifically have a law that the federal law is interfering with?
For example, I wouldn't expect California to file a suit against a federal AWB, even though they do already have laws that govern this. Georgia or Texas might be inclined to file a suit challenging a federal AWB, but I don't think these states have existing state laws that ban or regulate what models or types of firearms its citizens can purchase.