The people of LA get to run their issues as they please. This has nothing to do with federal installations or interstate issues, so SCOTUS not having applied the same standard is irrelevant.
As an analogy: SCOTUS has said that there is no bright line for what makes a reasonable amount of time in an investigative detention. Some states (NV as an example) have statutory time limits for how long you can be detained. Totally appropriate.
"To spit on your hands and lower the pike; to stand fast over the body of Leonidas the King; to be rear guard at Kunu-Ri; to stand and be still to the Birkenhead Drill; these are not rational acts. They are often merely necessary." Pournelle