I know for a fact that Thurmond was not supportive of segregation for his whole career. I'm not sure how much this piece speaks directly to that, but it's interesting with regard to his career, even while he was opposing integration:
https://historynewsnetwork.org/article/1166. Certainly, a complicated legacy.
STROM THURMOND: MODERATE ON RACE
Thurmond proved a wise choice as a presidential candidate. In a movement that was short on leaders of solid reputation, he brought a certain seriousness and legitimacy to the cause. But in terms of his political history, Thurmond was in many ways an odd fit with the other Dixiecrats. Although his subsequent political career has made him into the poster boy for the defense of white supremacy, Thurmond's gubernatorial politics and policies characterize him as a moderate. His 1946 gubernatorial campaign had been remarkably free of racist appeals. Compared to other southern governors elected during that politically schizophrenic year, Thurmond stood somewhere in the middle, halfway between Alabama populist James Folsom and Georgia racist Eugene Talmadge As governor he helped streamline government agencies, supported a minimum wage and maximum hour law, consistently urged abolition of the state's poll tax, advocated legislation to provide secret ballots in the general election, and championed the creation of a merit system for state government employment. In 1947, when a brutal lynching in upstate South Carolina shocked the nation, Thurmond quickly mobilized the state constabulary to apprehend the lynchers. Like other moderates in the 1940s and 1950s, Thurmond focused on modernization, undertaking an intense campaign to promote industrial development and economic growth in the state. Thurmond heartily believed that the South's racial dilemma would be solved through economic growth and development, not through federal interference.
Thurmond's assumption of the Dixiecrat mantle shocked South Carolina's small but active liberal community, which had great hopes when Thurmond was elected in 1946. In a letter to Thurmond, one African-American activist claimed he would have voted for Thurmond in the 1946 primary "were I not disfranchised" because "not once did you raise the race issue for political purposes." As late as October 1947, Thurmond remained a loyal Truman man. Thus, South Carolina liberals were shocked and disappointed when Thurmond moved to the front of the states' rights revolt in February 1948. State NAACP leader James Hinton criticized Thurmond's involvement as "a keen disappointment to the negroes of South Carolina." Up to that point, Hinton claimed, blacks felt that in Thurmond, "they had a Chief Executive, free from White Supremacy attitudes and expressions, and one who would hasten the day, when Negroes in South Carolina would enjoy 'EQUALITY OF OPPORTUNITY.'" South Carolina's tiny but active liberal community had come to expect better from its governor.
But even if his gubernatorial policies distinguished him from his fellow Dixiecrats, like his more conservative compatriots, Thurmond opposed all proposed federal civil rights legislation, which he considered unwarranted intervention and interference into the rights of states. In many ways, the South Carolinian personified the gendered components of the region's conservative states' rights political culture, making him particularly well suited to serve as point man in the states' rights crusade.
...
THURMOND WASN'T THE TYPE TO SAY "N*****"
With his moderate record, Thurmond's nomination mitigated, or at least complicated, outsiders' negative assessment of the southern party. In an editorial immediately following the Birmingham convention, the
New York Times said the States' Right platform illustrated a lack of "good sense," but regarded Thurmond's nomination as politically astute. A columnist from the
New York Star labeled Thurmond a "Dixie Paradox," who "embodies in one personality the Old South and the New." Both New York papers were impressed by Thurmond's record as governor: his opposition to the poll tax; his abhorrence of mob violence; his support of a minimum wage and maximum hour law; and his support for industrialization and for the removal of discriminatory regional freight rates.
The most colorful assessment of Thurmond's candidacy came from Baltimore editor and critic H. L. Mencken. The curmudgeonly Mencken considered Thurmond "the best of all the [presidential] candidates" but lamented that "all the worst morons in the South are for him." John Ed Pearce of the Louisville, Kentucky,
Courier-Journal, however, was less enamored of the South Carolinian. He noted that Thurmond's racism differed from the more outspoken white supremacists in style but not in substance. "On the platform Mr. Thurmond and his fellow travelers shout of Americanism, our way of life, the right to choose one's associates, Communism, Reds. But they mean N*****. Mr. Thurmond, of course, never says the word; he's not the type."
Pearce was right: Thurmond was not the type, but many in the Alabama and Mississippi Dixiecrat camps were, and to Thurmond, at least, the difference was important. Thurmond constantly differentiated himself from the Mississippi and Alabama Dixiecrats. Thurmond and his advisors clearly distinguished between their brand of conservatism and what they referred to as "the reactionary and conservative background" of the Alabama and Mississippi Dixiecrats. Beyond style, though, Thurmond's pro-development philosophy and his belief that the problem of the color line was at heart an economic problem differentiated him from the Mississippi and Alabama Dixiecrats who were tied to traditional Black Belt and industrial interests that did not pursue economic expansion and who were, at best, ambivalent about racial violence."
This speaks a little more to his change later in life:
https://www.greenvilleonline.com/st...mond-spent-lifetime-public-service/721586002/
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Changing parties
His disenchantment with the Democratic Party was complete. Thurmond bolted from the party in 1964, throwing his support to Arizona Sen. Barry Goldwater in his campaign to defeat Johnson. He went to work building the party in South Carolina.
"When he switched, it just made all the difference in the world," said Fowler. "He made the Republican Party legitimate in South Carolina and by implication, the rest of the South."
The importance of the switch became clear in 1968 when Thurmond aligned himself with Richard Nixon and held Southern delegates for Nixon against a challenge by Alabama Gov. George Wallace. Thurmond had become a national political force. Fowler said Thurmond delivered several Southern states to Nixon.
Edgar, the historian, said Thurmond's break to the Republicans in 1964 and his success in 1968 "changed the course of American history" in building the Republican Party in the South. His work for Nixon "gave him an inside track that no other Southern senator had."
Thurmond's moves to keep Wallace bottled up and promote Nixon in the South signaled an important political shift. The last move away from open racial politicking, however, would come after the 1970 South Carolina race for governor between Republican U.S. Rep. Albert Watson and Democratic Lt. Gov. John West.
Watson ran against busing, and the campaign whipped racist flames across the state. West said Thurmond worked harder for Watson than Watson worked for himself. Watson lost, and Thurmond began charting a new course.
He hired a black staff member in 1971, and he began working to change his image as a racist. He began broadening his legendary work for constituents to include black South Carolinians.
Modjeska Simpkins, a longtime advocate for civil rights in South Carolina, told The News before her death that she believed Thurmond had genuinely changed. "Down there somewhere, there was something fundamentally all right" about the senator. She said she asked Thurmond for help, and "he has never refused to help, and he has helped in every case."
I.S. Leevy Johnson was one of the first blacks elected to the South Carolina General Assembly in the 1970s. He said Thurmond was "not forgiven for the obstacles he put in the path of African-Americans to exercise the rights and privileges taken for granted by others." But he said Thurmond worked to address black concerns and was a strong supporter of black colleges.
Another black political pioneer, state Sen. Kay Patterson, said Thurmond's early record on race is indefensible. But Patterson said he believes Thurmond had "a change of heart on the road to Damascus, like Paul. He woke up and saw the light."
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Sen. Edward Kennedy said an important part of Thurmond's Senate legacy is his work with him to reform the nation's criminal sentencing laws.
Kennedy said he and Thurmond fought mandatory sentencing laws as a solution to sentencing disparities by crafting guidelines in the Sentencing Reform Act of 1984. Kennedy said he and Thurmond "came to the issue from different perspectives, but we agreed on the goal of fair sentencing laws. It took several years of debates, but Sen. Thurmond and I stood together."
