The thread is about whether our own Supreme Court understands the one single document which specifies the structure of all that is the United States of America. The Supreme Court exists solely to rule on questions of law and its conformity to the Constitution. Some complainant challenges a law, and the Supreme Court upholds it as conforming to the constitution, or overturns it as not conforming. No law or ordinance in any body of government within this country (federal, state, county, local) can contravene anything in the Constitution.
The fact that 4 of the 9 can, with a straight face, pull an "unless" phrase out of their butts and add it to the words "the right of the people to keep and bear arms, shall not be infringed," is just damned scary. There is no "unless" or "except Chicago" or anything else in there. It's the simplest possible language specifically to avoid interpretational issues, yet 4 of the people whose only job it is to uphold the supremacy of one single document have tried to rewrite it.