HBO’ Confirmation is adding to its impressive cast list once again. The Hollywood Reporter has learned that Treat Williams and Bill Irwin are the latest actors to join the upcoming TV movie about Clarence Thomas’ Supreme Court confirmation hearings. Confirmation, from HBO Films, details the explosive 1991 Supreme Court nomination hearings, at which Anita Hill testified, which brought the country to a standstill and forever changed the way people think about sexual harassment, victims’ rights and modern-day race relations. Williams has been cast as Ted Kennedy, who was one of Thomas’ biggest critics, while Irwin will play John Danforth, who used his clout in Washington D.C. to boost the confirmation of Thomas.