In the Senate, Yarborough established himself as a very different Democrat than the majority of his southern colleagues. After refusing to support a resolution opposing desegregation, he became one of only five southern senators to vote for the Civil Rights Act of 1957. He defeated wealthy conservative Democrat William A. "Dollar Bill" Blakley in the primary and Republican Ray Wittenburg in the election to win a full term in 1958. In 1960 Yarborough sponsored the Senate resolution leading to the Kennedy-Nixon television debate, a crucial event in the election and a model for subsequent presidential campaigns. In 1963 Yarborough was present at the Kennedy assassination; many believe his feud with conservative governor John B. Connally led to his sitting in the second car in the motorcade rather than with the president. Yarborough defeated George H. W. Bush, future president of the United States, in the senatorial race of 1964. In his years in the senate Yarborough supported many of the key bills of LBJ's Great Society and pressed for legislative action in the fields of civil rights, education, public health, and environmental protection. He voted for the Civil Rights Act of 1964 and was one of only three southerners to support the Voting Rights Act of 1965. Yarborough served for years on the Senate Labor and Public Welfare Committee, of which he became chairman in 1969. He sponsored or cosponsored the Elementary and Secondary Education Act (1965), the Higher Education Act (1965) the Bilingual Education Act (1967), and the updated GI Bill of 1966. He was also an advocate for such public-health measures as the Occupational Health and Safety Act, the Community Mental Health Center Act, and the National Cancer Act of 1970. A strong supporter of preserving the environment, he co-wrote the Endangered Species Act of 1969 and sponsored the legislation establishing three national wildlife sanctuaries in Texas-Padre Island National Seashore (1962), Guadalupe Mountains National Park (1966), and Big Thicket National Preserve (1971). His interest in the preservation of Texas historical sites led him to sponsor bills to make Fort Davis, Jeff Davis County and the Alibates Flint Quarries national monuments.
Through his support of the social welfare legislation of the 1960s Yarborough further identified himself with the goals of the national Democratic party and further distanced himself from the moderate-conservative state Democratic party. In 1970 Lloyd Bentsen, Jr., upset him in the senatorial primary and went on to gain the Senate seat. Yarborough's last attempt at political office, a run at John G. Tower's Senate seat in 1972, did not make it past the primary, where he was defeated by Barefoot Sanders. Yarborough returned to the practice of law in Austin. As an avid bibliophile and collector of Western Americana and Texana, he amassed a substantial library and numbered J. Frank Dobie among his friends and supporters. Dobie called Yarborough "perhaps the best-read man that Texas has ever sent to Washington." Yarborough wrote an introduction to Three Men in Texas: Bedichek, Webb and Dobie (1967) and contributed to Lincoln for the Ages (1964). He died in Austin on January 27, 1996. and was buried in the State Cemetery. He is regarded by many as one of the great figures in the Texas progressive tradition, a gregarious politician who campaigned in the old energetic, back-slapping style and who cared deeply about the social welfare of the people and believed that it could be significantly improved through government action.
30° 15.928, -097° 43.617
Texas State Cemetery