Trump's lawsuit is governed by a 1964 Supreme Court ruling, New York Times v. Sullivan. Dismissing Sullivan's claim, a unanimous Supreme Court established the key test that has governed US press freedom regarding public officials ever since. In 1964, the Supreme Court understood the importance of the context in which the case had been brought, namely the civil rights movement. In its Sullivan judgment, the Supreme Court understood the dangers to free speech in a time of polarised debate. Its ruling contains important warnings for Americans that extend well beyond the latest Trump lawsuit.