In American politics, the Southern strategy refers to a Republican Party
strategy of gaining political support for certain candidates in the
Southern United States by appealing to racism against African Americans.
Though the "Solid South" had been a longtime Democratic Party stronghold
due to the Democratic Party's defense of slavery before the American Civil
War and segregation for a century thereafter, many white Southern
Democrats stopped supporting the party following the civil rights plank of
the Democratic campaign in 1948 (triggering the Dixiecrats), the
African-American Civil Rights Movement, the passage of the Civil Rights
Act of 1964 and Voting Rights Act of 1965, and desegregation.
The strategy was first adopted under future Republican President Richard
Nixon and Republican Senator Barry Goldwater in the late 1960s. The
strategy was successful in winning the five formerly Confederate states of
the Deep South (Alabama, Georgia, Louisiana, Mississippi, and South
Carolina.) for Barry Goldwater in the 1964 presidential election, but he
won in only one other state, Arizona, his home state. The Southern
Strategy also yielded five formerly Confederate states (Florida, South
Carolina, North Carolina, Virginia, and Tennessee) in Richard Nixon's
successful 1968 campaign for the presidency. It contributed to the
electoral realignment of some Southern states to the Republican Party, but
at the expense of losing more than 90 percent of black voters to the
Democratic Party. As the twentieth century came to a close, the Republican
Party began attempting to appeal to black voters again, though with little
success.
https://en.wikipedia.org/wiki/Southern_strategy