James Phillip "Phil" Barton (January 18, 1920 - August 7, 1998) was an American politician and diplomat best known for serving as the Democratic leader of the Senate for almost two decades. He served as Senate Majority Leader on three occasions (1975-1981, 1983-1985, and 1987-1991) and as Senate Minority Leader on two occasions (1981-1983 and 1985-87). Representing Colorado for thirty years as a famously a strong-willed centrist, he placated both the left wing of his party by forcing Nationalist administrations into compromises and butted heads with the paleosegregationists who remained in the party in the late 1970's.
Serving as the party leader for sixteen consecutive years, his lofty position became even more firm after the assassination of Adam Eisler and the weakness of the ensuing three Democratic presidential candidates (Jimmy Carter, Joseph Clausen and Frank Reed). For a decade and a half, Barton was the public face of Democratic opposition to Elizabeth Shannon and Robert Redford, and was instrumental in transforming the Democratic party from a loose coalition of states-rights Southerners still trapped in the hangover of desegration and left-wing progressives, forming the "Grand Majority" that would force both Presidents Shannon and Redford into politically costly compromises in the 1980's, giving rise to post-segregation Southern Democrats who could run as safely centrist candidates and helping frame the public opposition to Redford throughout 1990. Following the 1990 landslide Democratic victory, Barton stepped down out of frustration from the influx of freshman liberals, in particular due to his dislike for the newly elevated Speaker of the House, Charlie Platt. He chose not to seek reelection in 1992 and died of lung cancer in 1998.