Throughout the 1960s, Thurmond generally received relatively low marks from the press and his fellow Senators in the performance of his Senate duties, as he often missed votes and rarely proposed or sponsored noteworthy legislation.
As Thurmond was increasingly at odds with the Democratic Party, on
September 16, 1964 he
switched his party affiliation to Republican. He played an important role in South Carolina's support for Republican
presidential candidates
Barry Goldwater in
1964 and
Richard Nixon in
1968. South Carolina and other states of the
Deep South had supported the Democrats in every national election from the end of
Reconstruction to 1960. However, discontent with the Democrats' increasing support for civil rights resulted in
John F. Kennedy barely winning the state in 1960. After Kennedy's assassination,
Lyndon Johnson's strong support for the Civil Rights Act and integration angered white segregationists even more. Goldwater won South Carolina by a large margin in 1964.
In 1968, Richard Nixon ran the first GOP "
Southern Strategy" campaign appealing to disaffected southern white voters. Although segregationist Democrat
George Wallace was on the ballot, Nixon ran slightly ahead of him and gained South Carolina's
electoral votes. Due to the antagonism of white SC voters towards the national Democratic Party,
Hubert Humphrey received less than 30% of the total vote, carrying only majority black districts.
At the
1968 Republican National Convention in
Miami Beach, Thurmond played a key role in keeping Southern
delegates committed to Nixon, despite the sudden last-minute entry of
California Governor
Ronald Reagan into the race. Thurmond also quieted conservative fears over rumors that Nixon planned to ask either
Charles Percy or
Mark Hatfield — liberal Republicans — to be his running mate, by making it known to Nixon that both men were unacceptable for the vice-presidency to the South. Nixon ultimately asked
Maryland Governor
Spiro Agnew — an acceptable choice to Thurmond — to join the ticket.
At this time, too, Thurmond took the lead in thwarting Lyndon Johnson's attempt to elevate Justice
Abe Fortas to the post of chief justice of the United States. Thurmond's devotion to the original structure of the federal Constitution, coupled with his general conservatism, had left him quite unhappy with the
Warren Court, and he was happy simultaneously to disappoint Johnson and to leave the task of replacing Warren to Johnson's presidential successor, Richard Nixon.