Jones plays Thaddeus Stevens. He won an Oscar for "The Fugitive" and has two other nominations ("JFK," "In the Valley of Elah").
De Niro plays Pat Peoples, the father of a former teacher who moves in with his mother following a stint in a mental institution. De Niro has two Oscars ("The Godfather Part II" and "Raging Bull") out of six nominations.
Waltz plays Dr. King Schultz, a bounty hunter who helps a former slave rescue his wife from a plantation owner. Waltz previously won this category for another Quentin Tarantino film. "Inglourious Basterds."
Hoffman plays the charismatic title character who leads a faith-based organization in 1950s America. He won Best Actor for "Capote" and contended in this category for "Charlie Wilson's War" and "Doubt."
Arkin plays Lester Siegel, one of the Hollywood producers who helps the CIA extract six Americans from 1979 Tehran. He won this race in 2006 for "Little Miss Sunshine" and has two Best Actor bids.