A court in Washington, DC, is considering whether President Trump violated the U.S. Constitution by ejecting the Associated Press from the White House press pool. Far more is at stake here than the rights of a single news organization. Trump wants to control what the world hears and learns about his government, and subjugating the press is a central part of his plan.

The press pool is a small group of journalists who cover the president on behalf of the larger press corps, and ultimately on behalf of the public. For more than a century, the pool has been the public’s eyes and ears in situations where broader access is not possible—for example, when the president speaks to the press in the Oval Office or when he is traveling abroad. Poolers were present when President Franklin Roosevelt died. They were present at the assassination of President John F. Kennedy and the shooting of President Ronald Reagan. They were with President George W. Bush when he learned about the September 11, 2001, attacks.

For at least four decades, the membership of the press pool has been decided by the press itself, through the White House Correspondents Association. A few weeks ago, though, Trump’s press secretary informed the AP that it would no longer be admitted to the Oval Office unless it revised its style guide to reflect Trump’s decision to rename the Gulf of Mexico the “Gulf of America.” Later the White House barred AP from Air Force One, and then from other spaces as well, complaining that AP had “weaponized” its style guide by refusing to adopt the president’s preferred language.

Of course, the real fight here isn’t about what things should be called, but about who decides. Who should decide how the press describes the world? Trump’s answer is “Trump”—but this is absurd and intolerable. Today Trump demands that the AP rename the Gulf of Mexico, but tomorrow he will demand that Ukraine be called Russia, that immigrants be called terrorists, and that the 2020 election be called a fraud. Plainly, the free press can’t cede to the White House the right to decide how reality should be described. A press that ceded that right would not be free, or serving the public, or worth defending.

If the courts apply the law faithfully, AP will prevail in this dispute. The organization I direct, the Knight First Amendment Institute, filed a legal brief last week pointing out that the First Amendment to the U.S. Constitution has long been understood to prohibit exactly the kind of retaliatory action the White House engaged in here. In the terminology of the First Amendment, the press pool is a “public forum,” and AP’s exclusion from it is impermissible discrimination on the basis of viewpoint.

But the fight over the press pool is just one facet of a broader campaign by the White House to control the information that Americans receive about their government. For years, Trump has used frivolous civil suits to subdue news organizations whose coverage he dislikes—suing ABC News for suggesting that a jury had found him guilty of rape rather than sexual assault; suing CBS News for making unremarkable edits to an interview with Kamala Harris; suing the Des Moines Register for publishing a poll that suggested that Trump would lose the election. Now the Trump-appointed head of the Federal Communications Commission has launched an array of investigations plainly meant to give Trump additional leverage in disputes about news coverage. Meanwhile, a major Trump donor is asking the Supreme Court to expand the circumstances in which public officials can prevail in defamation actions against the media.

And this campaign against press freedom is accompanied by a ruthless crackdown on dissent. Trump has issued two orders sanctioning law firms that he views as political enemies. His administration is arresting and threatening to deport foreign students for lawful speech. The State Department announced that it would use new artificial intelligence tools to revoke visas of immigrants determined to be “pro-Hamas”—a phrase that Trump administration officials use to characterize last year’s overwhelmingly peaceful protests against Israel’s bombardment of Gaza.

In recent years, American courts have sometimes come under criticism for unreflectively extending robust First Amendment protection even to commercial speech, data transfers, and campaign finance donations. But some of the Trump administration’s recent actions are assaults on the very heart of the First Amendment—on the right of citizens to associate freely and to criticize public officials, and on the right of the press to report the news. The AP case supplies the courts with an opportunity to make clear that they will defend these core political rights. A decisive response from the courts to Trump’s assault on the First Amendment is no guarantee that American democracy will survive Trump, but without one we are lost.