EXCLUSIVE: Tracy Letts is getting a quick promotion on Homeland. The Tony- and Pulitzer-winning actor-playwright, who was tapped for a recurring role on the upcoming third season of the Showtime drama a week ago, has now been upped to a series regular. He will play the role of Sen. Andrew Lockhart, the powerful, authoritative, and commanding Committee Chairman asking tough questions as the government’s investigation begins in the wake of the horrific terror attack that decimated the U.S. intelligence apparatus, and prompted a global manhunt for the world’s most wanted terrorist — Nicholas Brody (Damian Lewis). Letts is the first new series regular to join the cast of Homeland for Season 3. The Emmy-winning series also recently promoted recurring players F. Murray Abraham and Sarita Choudhury to regular. Letts is nominated for a Tony for his role in Who’s Afraid Of Virginia Woolf. He won a Tony and a Pulitzer for his play August: Osage County, and he also wrote the screenplay for the upcoming feature adaptation with an all-star cast to be released this fall. Season 3 of Homeland premieres on September 29, followed by the series debut of Masters Of Sex.