So if the White House wants to pursue this juvenile vendetta (a question that, alas, probably answers itself), it is going to have to offer a different reason—and as I read Sherrill, that reason needs to be compelling, like the safety of the president or the threat of serious disruption. Acosta may be loud, he may sass back at the president, he may ask follow-ups when Trump would prefer he didn’t—but there is a tradition of rowdy jostling and camera hogging in that pressroom that goes back to before the advent of TV. The legendary White House correspondent Merriman Smith once broke a leg in the pressroom as he rushed toward a telephone. I was once in the pressroom with the ABC News correspondent Sam Donaldson, next to whom Acosta is Mary Tyler Moore.

Our courts have said in many contexts that political discourse in this country must be “uninhibited, robust, and wide-open, and that it may well include vehement, caustic, and sometimes unpleasantly sharp attacks on government and public officials.” Trump’s sense of what he called “decorum” on Friday isn’t a government interest that overcomes that tradition.

Michelle Fields: Now I know why they said I lied.

Acosta also has an argument that Sherrill didn’t have. Sherrill didn’t have a pass but wanted one; Acosta had a pass—he’s been covering the White House since 2013—and suddenly lost it. The First Amendment interest in not being arbitrarily excluded is even higher when you’ve already been allowed in.

That’s where my beloved Island Tree High School library books come in. In 1975, members of the Island Trees Union Free School District attended a conservative meeting and left with a list of books the group considered “improper fare for school students.” Soon after, the board ordered the removal of nine books from the school libraries. A group of students sued to have the books restored, and the case made its way to the Supreme Court, in Board of Education, Island Trees Union Free School District No. 26 v. Pico by Pico.

In an opinion by Justice William Brennan, three justices said the First Amendment did not limit “the discretion of a local school board to choose books to add to the libraries of their schools” (my italics). But once the books are there, they said, “we hold that local school boards may not remove books from school library shelves simply because they dislike the ideas contained in those books.” Justice Harry Blackmun, in a separate opinion, wrote a less categorical opinion; but he said that removal of a book “is likely to suggest that an impermissible political motivation may be present.” Justice Byron White provided the fifth vote but refused to endorse the removal rationale. Four justices dissented.

What’s the relevance here? Before the district court in the CNN case, lawyers for the government took the position that the president or his staff could exclude any correspondent for any reason at any time. That claim is laughable; the president can call on anyone he wants, give interviews or not give interviews, and indeed not speak to reporters at all. But once he’s given a pass, he, like the vigilant Island Trees school board, needs to have at least a reason—and preferably a good one—to take it away.

Kelly might have an appetite to narrow the Sherrill ruling; Pico cautions against that. As precedent, it’s not rock solid. But as common sense, it is adamantine.

Remember, Acosta had his pass and used it without incident for five years. Think of it the way Blackmun did; the decision to remove the pass now is pretty suspicious. It might not even pass the rational-basis test.