Do you know what is also law? Manhattan Community Access Corp. v. Halleck, for which Trump-appointed (and voted by GOP senators in an overwhelming majority and voted against by Dem senators unanimously) Justice Brett Kavanaugh:

Under the Court’s cases, a private entity may qualify as a state actor when it exercises “powers traditionally exclusively reserved to the State.” … It is not enough that the federal, state, or local government exercised the function in the past, or still does. And it is not enough that the function serves the public good or the public interest in some way. Rather, to qualify as a traditional, exclusive public function within the meaning of our state-action precedents, the government must have traditionally and exclusively performed the function.

The Court has stressed that “very few” functions fall into that category. … Under the Court’s cases, those functions include, for example, running elections and operating a company town. … The Court has ruled that a variety of functions do not fall into that category, including, for example: running sports associations and leagues, administering insurance payments, operating nursing homes, providing special education, representing indigent criminal defendants, resolving private disputes, and supplying electricity. …

When the government provides a forum for speech (known as a public forum), the government may be constrained by the First Amendment, meaning that the government ordinarily may not exclude speech or speakers from the forum on the basis of viewpoint, or sometimes even on the basis of content[.]

By contrast, when a private entity provides a forum for speech, the private entity is not ordinarily constrained by the First Amendment because the private entity is not a state actor. The private entity may thus exercise editorial discretion over the speech and speakers in the forum. This Court so ruled in its 1976 decision in Hudgens v. NLRB. There, the Court held that a shopping center owner is not a state actor subject to First Amendment requirements such as the public forum doctrine[.]

The Hudgens decision reflects a commonsense principle: Providing some kind of forum for speech is not an activity that only governmental entities have traditionally performed. Therefore, a private entity who provides a forum for speech is not transformed by that fact alone into a state actor. After all, private property owners and private lessees often open their property for speech. Grocery stores put up community bulletin boards. Comedy clubs host open mic nights. As Judge Jacobs persuasively explained, it “is not at all a near-exclusive function of the state to provide the forums for public expression, politics, information, or entertainment[”.]

In short, merely hosting speech by others is not a traditional, exclusive public function and does not alone transform private entities into state actors subject to First Amendment constraints.

If the rule were otherwise, all private property owners and private lessees who open their property for speech would be subject to First Amendment constraints and would lose the ability to exercise what they deem to be appropriate editorial discretion within that open forum. Private property owners and private lessees would face the unappetizing choice of allowing all comers or closing the platform altogether. “The Constitution by no means requires such an attenuated doctrine of dedication of private property to public use.” … Benjamin Franklin did not have to operate his newspaper as “a stagecoach, with seats for everyone.” … That principle still holds true. As the Court said in Hudgens, to hold that private property owners providing a forum for speech are constrained by the First Amendment would be “to create a court-made law wholly disregarding the constitutional basis on which private ownership of property rests in this country.” … The Constitution does not disable private property owners and private lessees from exercising editorial discretion over speech and speakers on their property. …

A private entity … who opens its property for speech by others is not transformed by that fact alone into a state actor.

(Stephen T. Stone, I know this is what you usually do, but I’m out of Dragon Balls)