“But the states are sovereign and have the right to pass their own more restrictive laws if they so choose. This was widely understood at the time of the drafting and ratification of the Constitution.”

What wasn’t immediately clear to me from the decision is what happens to “no gun zones” on state-owned schools or facilities. It might be argued that certain types of land use or population densities, such as airports, are inherently places where guns cannot be allowed. Whether the argument can be made for an entire city like Chicago is something that lawyers will have to debate. Be interesting to watch though.