He means McDonald v. Chicago. Basically, if the Feds say you can own a gun, your city can't stop you from owning a gun.

Goobster's discussion is much more about the mechanics of minimizing gun violence. The relevant law, since John Roberts took over, has been that city and state bans can be superseded by federal permission. However, they didn't declare The Purge and drop the mic. Scalia:

The Second Amendment right is not unlimited. It is not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose: For example, concealed weapons prohibitions have been upheld under the Amendment or state analogues. The Court’s opinion should not be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms.

So. California's gun restrictions still stand. Massachusetts gun restrictions still stand. Pretty sure NY's restrictions still stand.

What you or Sam Harris want isn't really the issue here - it's what can be made to happen. McDonald v. Chicago wasn't nearly as sweeping as it could have been. It's been seven years and you're not entirely aware of it. I'm no legal scholar but Scalia's opinion, to me, says "this is not an originalist end-run around gun laws and what's in the constitution is not clear enough to be considered a complete mandate. Fucking legislate, people."