I would say the Heller case decision prohibited guns bans EVERYWHERE in the USA. It is just that Chicageo is ignoring the now-settled law.
The Circuit Courts have been lying their asses off for decades, using the Presser case in a rankly dishonest and corrupt fashion.
Mr. Presser conducted a parade in Chicago. His parade was with armed people. The law said he needed a parade permit, and he said, "no, the 2nd amendment give me the right to parade, as long as my parade is armed."
Faced with that argument, here is what SCOTUS said, in Presser v. Illinois, 116 U.S. 252 (1886). You'll be able to figure out which clause the Circuit Court cherry picked out of the opinion, to support the outcome they wanted (to disarm the public).
The below is presented as a continuous excerpt, not a single word, character or paragraph lies between the two reproduced below.
We think it clear that the sections under consideration, which only forbid bodies of men to associate together as military organizations, or to drill or parade with arms in cities and towns unless authorized by law, do not infringe the right of the people to keep and bear arms. But a conclusive answer to the contention that this amendment prohibits the legislation in question lies in the fact that the amendment is a limitation only upon the power of congress and the national government, and not upon that of the state. It was so held by this court in the case of U. S. v. Cruikshank, 92 U.S. 542 , 553, in which the chief justice, in delivering the judgment of the court, said that the right of the people to keep and bear arms 'is not a right granted by the constitution. Neither is it in any manner dependent upon that instrument for its existence. The second amendment declares that it shall not be infringed, but this, as has been seen, means no more than that it shall not be infringed by congress. This is one of the amendments that has no other effect than to restrict the powers of the national government, leaving the people to look for their protection against any violation by their fellow-citizens of the rights it recognizes to what is called in City of New York v. Miln, 11 Pet. [116 U.S. 252, 102] 139, the 'powers which relate to merely municipal legislation, or what was perhaps more properly called internal police,' 'not surrendered or restrained' by the constitution of the United States.' See, also, Barron v. Baltimore, 7 Pet. 243; Fox v. State, 5 How. 410; Twitchell v. Com., 7 Wall. 321, 327; Jackson v. Wood, 2 Cow. 819;Com. v. Purchase, 2 Pick. 521; U. S. v. Cruikshank, 1 Woods, 308; North Carolina v. Newsom, 5 Ired. 250; Andrews v. State, 3 Heisk. 165; Fife v. State, 31 Ark. 455.It is undoubtedly true that all citizens capable of bearing arms constitute the reserved military force or reserve militia of the United States as well as of the states, and, in view of this prerogative of the general government, as well as of its general powers, the states cannot, even laying the [2nd amendment] out of view, prohibit the people from keeping and bearing arms, so as to deprive the United States of their rightful resource for maintaining the public security, and disable the people from performing their duty to the general government. But, as already stated, we think [116 U.S. 252, 266] it clear that the sections under consideration do not have this effect.
The Circuit Courts cite the Presser case for the proposition that states are perfectly free to infringe the RKBA.