On Tuesday, individuals who have been blocked by the president on Twitter filed a civil action in federal court in New York. That means Judge Naomi Reice Buchwald will soon opine on the president’s unconstitutional viewpoint discrimination. The complaint alleges that “President Trump’s Twitter account, @realDonaldTrump, has become … an important public forum for speech by, to, and about the President” and by blocking individuals from receiving and replying to his tweets, the president is engaging in viewpoint-based discrimination prohibited by the First Amendment. Constitution protects certain platforms of communication in order to promote, as the Supreme Court put it, “the free exchange of ideas.” In a traditional public forum, like a public street or park, or in designated public forums, which are f ms designated by the government as a channel of communication for public debate, speakers can be excluded “only when the exclusion is necessary to serve a compelling state interest and the exclusion is narrowly drawn to achieve that interest.”

As I’ve detailed on the Lawfare blog, although the president has not formally designated the @realDonaldTrump Twitter account as a public forum, this is no mere private account. The president’s own spokesperson, Sean Spicer, has stated that the posts of the president on that account should be “considered official statements by the President of the United States.” The president uses this account to speak to matters in his official capacity—such as discussing his meetings with foreign leaders, providing reasons for hiring the FBI director, sharing video of cabinet meetings, and, of course, “covfefe.” Courts have taken heed; the Court of Appeals cited one of the president’s tweets in determining the purpose of the president’s “Travel Ban.”

Blocking people from receiving the “official statements” of the president based on their viewpoints is patently unconstitutional. Moreover, with some 20,000 replies posted to a typical @realDonaldTrump presidential tweet, there is undoubtedly a thriving public forum where citizens are engaging with the president and each other about matters of national importance. To deny an individual or an institution the right to participate in this forum affects not only their right to free speech, but it also affects the rights of the listeners—those individuals and institutions who were deprived of being able to hear the speech that was stifled.

The individual plaintiffs identified in the complaint have all alleged that they have been blocked by the president based on replies they tweeted criticizing the president or his policies. And there are many others that have been similarly blocked. For example, the veteran advocacy group VoteVets, which claims to represent more than 500,000 veterans, reports that it was blocked by the president after it tweeted a criticism of the president and his policies.

The next steps for the president seem clear: Stop engaging in viewpoint discrimination and unblock those individuals and institutions punished for criticizing him or his policies. If he doesn’t, the courts will issue a declaration that his actions are unconstitutional and order him to comply. To quote one of the president’s tweets: “See you in Court.”

Robert M. Loeb is partner at Orrick, Herrington & Sutcliffe, LLP, in its Supreme Court and appellate litigation practice, and was previously an appellate counsel at the U.S. Department of Justice. Anjali Dalal is an associate at Orrick, Herrington & Sutcliffe, LLP, a former judicial law clerk to Judge Sack of the U.S. Court of Appeals for the Second Circuit, and has published on issues of how the First Amendment applies to Internet postings.