On Thursday, former senator William Emerson Brock III died at 90. As a man who dedicated his life in unprecedented ways to building the Republican Party, his death raises questions about the political career he led and the history of the GOP’s path to its current iteration — one that Brock found disheartening in his final years.

The Brock family’s changing politics charted the generational decline of the Democratic Party in the South. In the 1930s, Brock’s grandfather served briefly in the U.S. Senate as a Democrat, at the time the strongest party in the region. His father, by contrast, a wealthy candy manufacturer, committed himself to community institutions such as the U.S. Chamber of Commerce and rejected party loyalties. Bill Brock III’s concerns with corruption and the expansion of the federal government motivated his decision to flee the Democratic Party entirely when he began his political career as a prominent young Republican leader in Tennessee during the late 1950s.

In 1962, campaigning as a new sort of Republican, Brock won a congressional seat that Democrats had held for over 30 years. His brand of Republicanism was a progenitor of Richard Nixon’s Southern strategy. At first, most pundits and politicians called Brock’s politics staunchly conservative, even right-wing. He developed a reputation as an acolyte of Sen. Barry Goldwater (R-Ariz.), who opposed any legislation that expanded the federal government, from farm subsidies to the Civil Rights Act of 1964. Brock emphasized his opposition to the Great Society, the end of school prayer and busing to desegregate schools — all Democratic initiatives that appalled many Southern Whites and motivated the backlash politics against the party.

Yet Brock’s winning formula included a youthful optimism and projected a happy warrior affect that soothed fears the GOP’s Southern success in the 1960s fed on and fueled painful racial divisions in the South. Brock went on to ride this formula to unseat the longtime incumbent Sen. Albert Gore Sr. in 1970, one of the few victories President Richard Nixon could claim in a dismal midterm election.

Brock then became a leading proponent of expanding the GOP’s constituency and led Nixon’s vast and unprecedented youth campaign, Young Voters for the President, in 1972. He also blended conservative positions on fiscal and defense issues with moderate ones on cultural issues. He supported women’s right to abortion and the Equal Rights Amendment. In a reversal of his earlier position on race, he supported affirmative action policies. He even denounced his own vote against the 1964 Civil Rights Act as the “worst decision of my life.”