When President Trump delivered an address in Krasinski Square in central Warsaw last summer, Poland’s nationalist government bused in supporters to swell the ranks of the crowd. There were protesters, but police managed to isolate most of them in side streets, invisible to Trump and most of the television cameras. When Trump declared that “America loves Poland, and America loves the Polish people,” the Polish people — or at least those permitted in the square — answered with rapturous applause.

We tend to associate political spectacles such as this with authoritarian regimes, and it was disquieting to see an American president playing a starring role in this one. A similar spectacle, though, has been unfolding continuously since Trump took office — on the president’s Twitter account.

Many of the president’s Twitter followers — millions of them, by some counts— are bots programmed to create the impression that Trump and his statements are more popular than they are. And while social-media dissenters aren’t penned in side streets, the president “blocks” some of his sharpest Twitter critics, disabling them from participating in the forum created by his account. This latter practice is a digital version of the same ugly censorship the president appeared to endorse in Warsaw, and its constitutionality will be the subject of a hearing in federal court on Thursday.

The president has said he uses Twitter because it allows him to communicate directly with the public. The 280-character tweet has become as important to him as radio was to Franklin D. Roosevelt and television was to John F. Kennedy. He has used Twitter to introduce new policies, announce nominations to key government posts and inveigh against convenient political scapegoats, including immigrants and the media. Over time, his account has become an important source of news and information about the administration — and about the president’s disposition as well.

In June, then-White House press secretary Sean Spicer characterized the president’s tweets as “official statements,” and in recent weeks the administration has repeated that characterization before federal courts.

But the president’s Twitter account isn’t merely a broadcast mechanism. It’s also a forum in which millions of Twitter users interact with the president and with each other — a digital town square, with the president speaking from a stage and assembled citizens responding to him and conversing with one another about his statements. From a distance, the debate in this square can seem like the kind of“uninhibited, robust and wide open” discourse that our First Amendment tradition celebrates. But the president’s efforts to suppress dissent give the spectacle a darker cast.

This week’s hearing relates to a First Amendment lawsuit the Knight Institute filed on behalf of Twitter users whom the president blocked for criticizing him. (There’s no dispute that the president blocked them or that he did so because of their viewpoints, because the White House has effectively conceded these facts in a filing with the court.)

But while the case focuses on Trump’s social media practices, it’s likely to have broader ramifications. As the Supreme Court observed last term, public officials around the country now engage with their constituents principally through social media. Exchanges between elected officials and their constituents that once took place offline routinely occur on Twitter and Facebook. It is settled law that the First Amendment bars government officials from excluding speakers from city council meetings, school board meetings and similar public forums on the basis of their viewpoints. A lot depends, now, on whether and how this law applies to digital-era technologies.

The case is a test for other foundational principles as well. In court, the president argues that the First Amendment permits him to block speakers who have affronted him, but he also contends that, even if he is acting unconstitutionally, the court lacks authority to order him to stop. Recycling arguments made by President Richard Nixon, he argues that an order barring him from blocking critics would represent an intolerable intrusion into powers the Constitution commits exclusively to him. (Precisely which powers, he doesn’t say.) The Supreme Court rejected similar arguments when Nixon made them, and Trump has an even weaker hand in this case. That he is advancing this argument at all only underscores that the case is not just about control of a social media forum but about deeper undemocratic impulses as well.

The question of how the First Amendment applies to public officials’ social media accounts is a novel one. The problem of government officials seeking to limit and manipulate core political speech, however, is all too familiar. We should understand the president’s Twitter account through that lens, and the courts should too.