President Trump violated the constitutional rights of Americans when he blocked some of his Twitter followers after they criticized him politically, a federal judge ruled Wednesday.

The ruling by U.S. District Judge Naomi Buchwald identifies, for the first time, parts of Trump's Twitter account as a public forum that is subject to First Amendment protections.

But in many ways, the ruling raises many more questions about the extent of those First Amendment obligations. Here's what you need to know to get up to speed.

What did the judge's ruling say?

Trump cannot legally block his Twitter followers for political reasons, the judge ruled, because that would amount to “viewpoint discrimination” by a government official in a public forum.

That's a lot to unpack. But the essential idea is that Trump's use of Twitter in an official capacity — by writing “45th President of the United States of America” in his Twitter bio, for example, or issuing statements on matters of public policy and so on — subjects him to constitutional obligations that aren't imposed on average Americans or even private celebrities.

Does this ruling mean that all of Twitter is a public forum under the law? Is Twitter subject to the First Amendment now? 

No. The ruling pointedly does not rule on Twitter as a whole, nor even the entirety of Trump's Twitter account. It only looks at portions of his account: “The content of the tweets sent, the timeline comprised of those tweets, the comment threads initiated by each of those tweets, and the 'interactive space' associated with each tweet in which other users may directly interact with the content of the tweets by, for example, replying to, retweeting, or liking the tweet.”

The court did not find that Twitter is beholden to the First Amendment. It affirmed the principle that the Constitution applies only to the government and not private individuals. So under Buchwald's ruling, Twitter remains free to block users from its platform, on its own terms, without running afoul of the First Amendment.

Doesn't this set a precedent where all of Twitter could become a public forum subject to the First Amendment?

It's hard to see how, according to legal experts. In determining whether a space is a public forum for First Amendment purposes, judges apply a multipart test. One factor in the test is whether the supposed forum is owned or controlled by the government. Twitter, as a private entity, fails the test. For Twitter to become subject to the First Amendment would all but require the government to nationalize the company — an extremely unlikely prospect, said Joshua Geltzer, an expert in constitutional law at Georgetown University.

“The decision finds that President Trump, as a government official, created the type of public forum on the @realDonaldTrump feed that only the government can create, and to which the First Amendment then applies,” Geltzer said. “The decision may have implications for other government officials' blocking of critics on social media, but it doesn't even come close to making all of Twitter a public forum, as the vast majority of the Twittersphere is not being converted into a public forum by government actors.”

What about Trump's own First Amendment rights? Don't those guarantee him the ability to treat his followers the way he wants?

Trump didn't give up his First Amendment rights by becoming president, the judge said, but upon taking office he gained a number of other constitutional responsibilities — such as not engaging in governmental viewpoint discrimination that's prohibited by the First Amendment.

“No government official — including the President — is above the law,” wrote Buchwald for the U.S. District Court for the Southern District of New York.

Again, private entities such as Twitter are not subject to this expectation. But government officials like Trump are.

Trump's critics can still view his tweets by visiting Twitter without logging in. So what harm did Trump cause, really?

Twitter users can indeed view Trump's profile publicly without having an account. But, Buchwald wrote, Trump could have ignored the offending followers or muted them. Instead, he blocked them — "limiting the blocked user’s right to speak in a discrete, measurable way."

And sure, the affected users could easily get around the block by creating new accounts to participate in the public forum surrounding Trump's tweets. But, legal analysts say, just because there's an easy workaround doesn't absolve Trump of the constitutional violation, which still occurred.

Could this ruling prompt some people who've been banned from Twitter to argue that Twitter is infringing on their rights to participate in the public forum surrounding Trump?

Yes, according to Noah Feldman, a Harvard University law professor. “That is crazy,” he said. “But it is a possible logical outcome of this decision.”

That said, given Twitter's status as a private entity, it's unclear how far those arguments might get with a judge.

To what extent does this decision affect other politicians and public officials?

The ruling itself doesn't mention other public officials. But it does set a precedent that other public officials will be under pressure to obey, said Katie Fallow, a senior staff attorney with the Knight First Amendment Institute who argued the case in the U.S. District Court for the Southern District of New York.

Trump is not the only elected official to face litigation concerning social media blocking. In April, Maryland Gov. Larry Hogan (R) settled a federal lawsuit with the American Civil Liberties Union after Hogan blocked more than 400 people from his Facebook page. As part of the settlement, the state agreed to pay $65,000 to the Facebook users who sued, and to cover legal fees.

Staff writer Hamza Shaban contributed to this report.