The death of the journalist Nat Hentoff, who slipped away Saturday at 91, takes one of America’s greatest tribunes of the Constitution at one of its hours of maximum peril. Hentoff rose to fame as a jazz critic of for the Village Voice. We tend to think it was no coincidence that his love of jazz, which toppled musical conventions, throbbed in the same heart that led him to challenge so many political conventions, particularly, though not exclusively, the political correctness of the Left. How we will need newspapermen like Hentoff in the years ahead.

It would be vainglorious to suggest that we knew Hentoff well. We first met him in the 1980s, when he sent an appreciative note in respect of an editorial issued in the Wall Street Journal. It was about a case in which the police superintendent in Bridgeport, Connecticut, was offered a bribe of $5,000. The superintendent rejected the bribe and arrested the hapless fellow who proffered it, only to discover that “briber” was attempting a sting for the FBI. Bridgeport sought to have the FBI agents arrested, which tickled the Journal’s fancy and delighted Hentoff.

As Hentoff’s career waxed, he more and more frequently “infuriated leftist friends,” as the New York Times obituary put it this morning, “with his opposition to abortion, his attacks on political correctness and his criticisms of gay groups, feminists, blacks and others he accused of trying to censor opponents.” Given the fact that Donald Trump just rose to the presidency on what at least in part was a campaign against political correctness, it would not be too much to say that Hentoff played the part of a prophet.

Not that Hentoff was in the pro-Trump camp. Heaven forefend. The columnist was no longer in full fettle at the time Mr. Trump made his move for the presidency, but a quick search on the Internet suggests that he took a clear-eyed and skeptical view of both candidates, left and right. It’s no small thing that by then his columns, which once appeared in the greatest of our liberal papers (including the Washington Post), were being carried by the right-wing Web site WorldNetDaily.com.

One of the most courageous and dramatic developments in Hentoff’s career was his emergence as a defender of the pro-life movement. The turn seemed at times to be all the more newsworthy because of his self-declared atheism and his long-established progressive bona fides. In a column written not long after he turned 90, Hentoff quoted the archbishop of New York, John Cardinal O’Connor, as saying “You’re the only Jewish, atheist, civil libertarian, pro-lifer, tireless free speech advocate we have.”

Yet our own favorite moment with Hentoff came when he got himself into a lather over treason. This was in 2006, after the Bush administration had levied its charge of treason — against Adam Gadahn, an American who’d thrown in with al-Qaeda. Hentoff started worrying about what he called “the prospects for treason trials of Americans under the presumptions of guilt embedded in the new law for ‘supporters’ of terrorists.” He vowed to follow the story while “avoiding paranoia and reverse agitprop,” which, we harrumphed, would be “refreshing.”

We sent over to Hentoff’s “chambers” a copy of Ex Parte Bollman and Swartwout, in which Chief Justice Marshall let two of Aaron Burr’s confederates skate from treason owing to the fact that war hadn’t been levied. Marshall warned, though, that it was not necessary to appear in arms to commit treason. “On the contrary,” Marshall warned, “if war be actually levied” then “all those who perform any part, however minute, or however remote from the scene of action, and who are actually leagued in the general conspiracy, are to be considered as traitors.”

We called our editorial “Ex Parte Hentoff.” What a blast of countervailing opinions it precipitated from Hentoff’s capacious inkwell. What we remember about the moment is not just the pepper and passion of Hentoff’s engagement on the question of treason but his lack, toward those who disagreed with him, of anything but friendliness and goodwill. That capacious spirit, as much as Hentoff’s attachment to principle, was the mark of his own brand of liberalism and a reason why he will be so widely missed.