I haven’t been an employee of The Post for a dozen years. What I am is a conservative who has worked in and around mainstream journalism for 40 years. And what I see in Warzel’s tweet — and in the astounding silence on the part of most mainstream outlets and voices about the treatment of The Post by Twitter — is something neither I nor anyone else anticipated from the web takeover of communications over the past 30 years.

With the emergence of the web browser in the early 1990s, the internet shattered the hierarchy that once dominated American journalism. A world in which the transmission of information had been the province of a wire service, three networks, two newsmagazines and a few powerful newspapers seemed gone forever.

New voices found a new way to be heard. Lone bloggers armed with nothing more than laptops took down the Senate majority leader (for suggesting a racist colleague’s values were ones we needed) and the nation’s most ­famous anchorman (for promoting a forged document).

Then, in 2007, came Twitter. And something very curious happened as it quickly became a bulletin board, gathering place and loose-knit private club for US journalists.

It became a peerless vehicle for the enforcement of mainstream media groupthink.

Twitter was the place where you could establish informal relationships with others in your field with whom you had never worked but whose attention you very much craved.

And you could quickly tell what subjects were of particular concern to those same fellow journalists by the way their tweets echoed each other’s. If a news development appeared 20 times in your latest 30 tweets, you would know it was the topic of the day or the week.More important, if a subject violates the sensibilities of the Twitter journalism community, you sure know that too. Immediately. Offense is taken. Fingers are wagged. Instantaneously, the idea that something is a “bad take” becomes universally understood.

Reputations and careers are on the line — as is the possibility of enhancing your reputation and/or career by joining in the groupthink.

Before the social-media age, the groupthink of the old-media oligopoly was transmitted relatively slowly. The network newscasts and the New York Times were released once a day, after all. So the orthodox take on things might take a few days to reach everybody, and in that time, some other reporting, some other opinions, some other takes might break through.

Now all reporting is instantaneous — and the only “correct” way to look at a news story follows with similar instantaneity.

One of the correct ways to look at things, it appears, is to quash them if and when they are politically and ideologically inconvenient.

It was members of the mainstream media who demanded their fellow journalists refuse to follow up on The Post’s initial story about the revelations on the Hunter Biden laptop — and used Twitter to attack some journalists who dared to retweet The Post story even if they were criticizing it.

George Orwell once referred to the “smelly little orthodoxies which are now contending for our souls.” That is how Twitter operates. That is what Twitter is — the home of and transmission point for the smelly little orthodoxies of our time.