TLDR Legal and constitutional.
IME, it's somewhat common for those in positions of authority (employers, municipalities, etc.) to simply assert a legal position that benefits their leadership, without mentioning that courts may disagree. In most cases there are no repercussions for being misleading in that way, aside from eroding the trust of those lied to.
"In case that any parish, town, or city, or any portion thereof, shall become infected with any contagious or infectious disease, to such an extent as to threaten the spread of such disease to the other portions of the state, the state board of health shall issue its proclamation declaring the facts and ordering it in quarantine, and shall order the local boards of health in other parishes, towns, and cities to quarantine against said locality"
That sure sounds like it's talking about local quarantines to me.
If you want to succeed in Western countries it's worth internalizing this. In the absence of legal advice to the contrary, just assume that what you're doing is legal and assert it confidently, and most people won't challenge you. If they do, it helps to have lots of money to afford lawyers on retainer, so that a.) you're more likely to actually be right when you assert that what you're doing is legal and b.) you can craft very good arguments to persuade the judge and jury if it turns out you're wrong.
- I've already accepted that fire codes can legitimately limit the number of people in a building.
- The rule is agnostic with respect to the purpose of the meeting. E.g., it's not obviously being used to suppress political or cultural movements.
- It has a real, plausible purpose for public safety.
That being said, I can also see some valid reasons against it:
- It sets precedent, which is a powerful factor in the U.S. court system.
- The 1000-person rule seems a bit arbitrary. I would think the number needs to be much smaller for the effect to be meaningful. And I'm guessing something more nuanced is what's really needed, for example spacing between persons, air recirculation / flow rates, frequency of surface cleaning vs. # persons present, etc.
- It implicitly discriminates what kinds of groups can meet as before. One salient example would be that Christian mega-churches and really large Roman Catholic parishes couldn't meet as before.
- It also potentially prevents mass protest marches, depending on the wording of the ordinance, and how willing protestors are to ignore the ordinance.
This is one scenario where I wouldn't be surprised if there are groups that refuse to uphold the order and file lawsuits over it infringing on their right to practice their religion (and assemble, of course).
I do not believe this is unconstitutional. It is not meant to keep people from exercising their First Amendment rights. It's speech neutral (time/place/manner restrictions are subject to a much lower level of judicial scrutiny than content-based restrictions).
It only applies to events in facilities owned or managed by the City of San Francisco. It does not prevent people from gathering in public spaces, nor prevent private venue operators who want to hold large gatherings from doing so (not that anyone with a modicum of liability insurance wants to take such risks).
I'm almost certain you're incorrect due to the fact that basketball games will be effected and those aren't run by the city - teams remain private entities.
This does effect intentional private gatherings in public spaces, so if you have an extended family with more than 1000 people in it then your family reunion would be effected.
That said, this is absolutely legal and constitutional and that clarity lies on the backs of many historical disease outbreaks in the US that have resulted in similar restrictions.
Congress shall make no law ...abridging ... the right of the people peaceably to assemble.
Nevertheless the reference itself comes from a really terrible case where the supreme court wrongly infringed on the rights of a war dissenter. It is not a concept that ought to be continued to be parroted.
Saying "no gatherings of more than 1000" is facially legal. Plenty of protests have been told it's time to disperse before.
Furthermore, SCOTUS typically grants even wider powers in extigent circumstances. It is probably also legal to say "no gatherings at all, everyone back to your houses for the duration of this crisis". An example would be something like the boston bomber crisis, although I don't think it was litigated, that probably would have been found to be legal as well.
And... honestly... not a lot of sensible people are going to complain. Only the very fringes are going to object. The vast "middle" majority, in this case 98%+, is going to agree, conform, and be upset at the people objecting to the quarantine and who break it, not at the government. That counts for a lot too, in practice.
It's frankly a very good idea. I'd even say to lower the number to 50 or maybe 100 at most. Some of the gatherings in South Korea that are believed to have been super-spreading events have been less than that (that church group).
> Some jurisdictions have resolved this tension through compromise: TB patients cannot be forced to undergo treatment, but they may be isolated or detained if they refuse treatment.