Spencer began his television career on The Patty Duke Show, and eventually began appearing in supporting roles in feature films commencing with 1983's WarGames. He won an Obie Award for the 1981 off Broadway production of Still Life, about a Vietnam War veteran, and received a Drama Desk nomination for The Day Room. In 1986 he appeared on Broadway as Dan White, the killer of Harvey Milk, in Execution of Justice, alongside Stanley Tucci and Wesley Snipes. Spencer became a full-fledged supporting actor with the hit 1990 courtroom thriller Presumed Innocent, portraying a tough veteran homicide detective, starring opposite Harrison Ford. The same year, Spencer joined the cast of the television series L.A. Law, playing rumpled, pugnacious, street-wise trial attorney Tommy Mullaney. Spencer's work also extended to video games, portraying the role of Captain Hugh Paulsen in the 1995 video game . Spencer's subsequent film and television work primarily consisted of supporting roles such as a colleague and friend to Billy Crystal's basketball ref in Forget Paris and a prickly FBI official in Michael Bay's film The Rock. In 1999, Spencer was cast as Leo McGarry on the NBC political drama series The West Wing. Spencer's character was White House Chief of Staff to the fictional U.S. President Josiah Bartlet. Both McGarry and Spencer were recovering alcoholics. Spencer's role on the show earned him the Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series in 2002, after he was being judged on the show's third season episodes "Bartlet for America" and "We Killed Yamamoto."
Death
Spencer died of a heart attack in a Los Angeles hospital on December 16, 2005, four days before his 59th birthday. At Spencer's private funeral, his West Wingcastmate, Kristin Chenoweth, sang the musical number "For Good" from the Broadway musicalWicked. Spencer's remains were interred at Laurel Grove Memorial Park in his hometown of Totowa, New Jersey. At the time of his death, Spencer had filmed two of the five West Wing episodes that were in post-production: "Running Mates" and "The Cold." Spencer's death was later written into the show's seventh and final season, in which McGarry was said to have died of a heart attack on election night. Coincidentally, McGarry had also suffered a near-fatal heart attack in the show's sixth season. Spencer's name remained in the opening credits throughout the remainder of the show.