CORRALES, N.M. (AP) — Fred Harris, a former U.S. senator from Oklahoma, presidential hopeful and populist who championed Democratic Party reforms in the turbulent 1960s, died Saturday. He was 94.

Harris’ wife, Margaret Elliston, confirmed his death to The Associated Press.

“Fred Harris passed peacefully early this morning of natural causes. He was 94. He was a wonderful and beloved man. His memory is a blessing,” Elliston said in a text message.

Harris served eight years in the Senate, first winning in 1964 to fill a vacancy. As chairman of the Democratic National Committee in 1969 and 1970, it fell to him to help heal the party’s wounds from the tumultuous national convention in 1968, when protesters and police clashed in Chicago.

Harris moved to New Mexico in 1976 and became a political science professor at the University of New Mexico.

He wrote and edited more than a dozen books, mostly on politics and Congress. In 1999 he broadened his writings with a mystery set in Depression-era Oklahoma.

Throughout his political career, Harris was a liberal voice for civil rights and anti-poverty programs to help minorities and the disadvantaged.