James Ellroy's Underworld USA Trilogy, containing of the books American Tabloid, The Cold Six Thousand and Blood's a Rover, is the best source and motivation for a TV show based on organized crime, political conspiracies and awesome (anti-)protagonists. This man is behind the story of the legendary movie L.A. Confidential.
The plot is about the assasination of JFK, Dr. Martin Luther King, Bay of Pigs, J. Edgar Hoover's fight for power and many more interesting events in the U.S. history during the Cold War period. (Don't want to spoiler too much, I can only recommend everyone to read the books).
This man can deliver stories above everything what we can imagine, and if HBO would start such a production featuring his books, it would maybe the best TV show in recent history. I'm someone who misses The Wire or The Sopranos and I'm convinced that James Ellroy's books would bring us a TV show at at least the same level as the TV shows mentioned above.
The time is right HBO, make it happen. It's an opportunity for us all, which should not be wasted.
