4. Neal McDonough as a Congressman
McDonough is a journeyman actor. He's been in dozens of projects ranging from the sublime ("Band of Brothers," Captain America: The First Avenger, the aforementioned "Justified") to the dark and twisted underbelly of alleged entertainment (I Know Who Killed Me, Street Fighter: The Legend of Chun-Li). But in all these roles, he has consistently been professional and brought everything he has to the table. Typically tapped to play psychos, businessmen, or psychotic businessmen, McDonough's hypnotic pale blue eyes and genial voice have been utilized as a charming facade draped over unhinged personalities. Equally, he's also played slightly aloof but generally decent men. I conclude that this actor is perfect to play a politician, and an old west politician would be icing on that cake.
Deadwood was annexed to the Dakota Territory during the seasons of the show that we got to see, but now that we are ten years out from that it would be interesting to see the opportunistic power struggles that actually occurred when Dakota was being considered for statehood. McDonough would do well as the outsider coming into the tiny world he doesn't understand and believes he can master. Because the two Dakotas were separated due to a perceived imbalance in Democratic and Republican representation in the territory, it would be fun to watch an outwardly humble and beatific man of the people try to run our resident outlaws, whores, and cowboys out of the Black Hills so that his political party could claim the more valuable lands. It sets up someone like McDonough to have fun as the generous man-of-the-people and also squint smarmy intelligence as the cold, patronizing dandy from Washington.