Gun reform advocates reacted with outrage to the supreme court decision overturning a New York state handgun law that placed strict restrictions on carrying concealed firearms outside the home.
If you go and look at the US supreme court and it's competence
According to the Constitution (Art. III, §2): "The judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution
In short, all law in the US is subject to the constitution and the supreme court rules on constitutional law.
So taking the next step, the second amendment of the constitution says:
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
The New York legislation continued the right to keep weapons, in your own home. However the right to "bear arms" was infringed. I have no idea what they thought they were doing because this is as clear a case of state law overriding constitutional law as there can be. The Supreme court didn't need to work hard on this at all.
The path to deal with arms is clear. First the white house and the Congress need to get together and agree on a change to the constitution to restrict the right to bear arms. Then that legislation needs to pass through the Senate before it can be written into law. Once that has happened, depending on the wording, states may then enact legislation to restrict the right to bear arms.
The fact that more than half of Americans, whether Republican or Democrat, don't want the second amendment to be touched, is the real problem here and it is not something individual states or cities can deal with. The nearest I have seen to this is Miami. Where they removed the right to bear hidden weapons, you might think in the same way. But they did not make it illegal to bear arms, they just forced anyone who wants to bear arms to do so openly in a visible holster. Thus avoiding this issue with the court.
America may seem odd, but it is also quite predictable.