Seven years ago, Chuck Klosterman got it right when he said that there would never be another thing like “Johnny Carson.” The host of The Tonight Show was the last “universally shared icon,” and we’re now seeing even more compartmentalization as the sheer amount of culture we have access to grows. We’re moving further and further from the moment when Carson was universally known, let alone talked about regularly in the cultural conversation. For a bit of context, Selena Gomez was born the year he went off the air. So even if everyone in the 1970s knew about Johnny Carson, are there enough movie-goers left to demand that a movie about him get made? That’s the question that John McLaughlin and Tom Thayer (Hitchcock) are betting they know the answer to. According to Deadline Hollywood, the pair is working with the Carson Estate and will be shopping a biopic script to studios soon. Based on the forthcoming book, “Carson the Magnificent: An Intimate Portrait” from Bill Zehme, the project will showcase the life of the notoriously private entertainer. Obviously, the big question is who (if they get off the ground) the production should cast as Carson. Judging solely from the photo above, Josh Brolin might be an inspired choice. Kevin Spacey too. But even when they figure out Carson, they’ll have to cast Ed MacMahon. Now there’s a real challenge.