Lawrence Aaron Nixon, Black physician and voting-rights advocate, was born in Marshall, Texas, on February 9, 1883, the son of Charles and Jennie (Engledow) Nixon. He attended Wiley College in Marshall and received his M.D. degree in 1906 from Meharry Medical College, Nashville, Tennessee. He began practice in Cameron, Milam County, Texas. In 1907 the alarming number of lynchings of Black men in Texas, one of which occurred in Cameron on November 4, influenced Nixon to become a civil-rights advocate. In December he moved to El Paso. There he established a successful medical practice, helped organize a Methodist congregation, voted in Democratic primary and general elections, and in 1914 helped to organize the local chapter of the National Association for the Advancement of Colored People. In 1923 the Texas legislature passed a law prohibiting Blacks from voting in Democratic primaries. On July 26, 1924, with the sponsorship of the NAACP, Nixon took his poll-tax receipt to a Democratic primary polling place and was refused a ballot. Thus began a twenty-year struggle in which Nixon and his El Paso attorney, Fred C. Knollenberg, twice carried their case to the United States Supreme Court.
In 1927, in Nixon v. Herndon, Justice Oliver Wendell Holmes wrote the decision that Nixon had been unlawfully deprived of his rights under the Fourteenth Amendment. In 1932 Justice Benjamin Cardozo ruled for Nixon again, in Nixon v. Condon, holding that political parties are "custodians of official power . . . the instruments by which government becomes a living thing." The Nixon cases were major steps toward voting rights, but there were legal loopholes under which the state and the Democratic party continued to deny primary votes to Blacks. It was not until the decision in Smith v. Allwright ended the white primary that the way was cleared, and on July 22, 1944, Dr. and Mrs. Nixon walked into the same El Paso voting place and voted in a Democratic primary. Nixon was married first to Esther Calvin, who died on February 21, 1919, then in 1935 to Drusilla Tandy Porter, who survived him. He had four children. Nixon died on March 6, 1966, as a result of an automobile accident.