(CBS Local)– Writer Gabriel Sherman spent years of his life reporting on Fox News and the face of its network Roger Ailes.

Sherman ended up writing a book on Ailes and the rise of Fox and that has been turned into the new Showtime limited series starring Russell Crowe called “The Loudest Voice.” Sherman serves as a writer and co-executive producer on the show and it’s still pretty wild for him that all his work has culminated with a show on major network television.

“It’s surreal to see Russell Crowe playing Ailes on the screen because I’ve been covering this world for almost 10 years now,” said Sherman in an interview with CBS Local’s DJ Sixsmith. “I first started covering cable news at New York Magazine. My reporting shifted into more of a biography on Ailes. Once he found out I was writing about him, it became this super intense experience where he went scorched earth on me.”

Sherman says that Ailes hired private investigators to tail him and he and his wife even received a death threat over the phone. While the Vanity Fair special correspondent was terrified, it motivated him to keep reporting. Ailes’s legacy is extremely complicated and reporting on the man was no easy task for Sherman.

“I’ve never covered organized crime or national security, but I imagine that’s what this must be like,” said Sherman. “I had sources tell me to meet me at out of the way pubs in random parts of the city. I had one source who would only communicate with me through anonymous encrypted chats. It was fascinating because you think of a news organization as open and transparent and it was operating more like a cult. He [Ailes] was a much different person behind the scenes than he was in public.

“The Loudest Voice” premieres on Sunday and the show bounces around from the start of Fox News, to the days after 9/11, the build up to the election of President Barack Obama and Ailes’s death. Sherman wants viewers to take one big thing away from the show.

“In the writer’s room, we wanted to put an emphasis on this was Trumpism before Trump,” said Sherman. “We want this show to really illustrate how Fox News and Roger Ailes created the world that allowed Donald Trump to become president.