For nearly a century after Reconstruction, the white South identified with the Democratic Party. The Democrats’ lock on power was so strong the region was called the Solid South, although the Republicans controlled parts of the Appalachian mountains and they competed for statewide office in the border states. Before 1948, southern Democrats believed that their party, with its respect for states’ rights and appreciation of traditional southern values, was the defender of the southern way of life. Southern Democrats warned against aggressive designs on the part of Northern liberals and Republicans and civil rights activists whom they denounced as “outside agitators.”
The adoption of the strong civil rights plank by the 1948 convention and President Harry S. Truman’s Executive Order 9981, which provided for equal treatment and opportunity for African-American servicemen, drove a wedge between the northern and southern wings of the party.[11]
By 1948 the national Democratic Party began to embrace the civil rights movement, and its argument that Southern whites had to vote Democratic to protect segregation grew weaker. Modernization had brought factories, national businesses, and larger, more cosmopolitan cities such as Atlanta, Dallas, Charlotte, and Houston to the South, as well as millions of migrants from the North and more opportunities for higher education. They did not bring a heritage of racial segregation, and instead gave priority to modernization and economic growth.[12]
Integration and the civil rights movement caused enormous controversy in the white South, with many attacking it as a violation of states’ rights. When segregation was outlawed by court order and by the Civil Rights acts of 1964 and 1965, a die-hard element resisted integration, led by Democratic governors Orval Faubus of Arkansas, Lester Maddox of Georgia, and especially George Wallace of Alabama. These populist governors appealed to a less-educated, blue-collar electorate that on economic grounds favored the Democratic Party, but opposed desegregation.
Sensing an opening in the “Solid South,” the Republican Party gained political support among many white people in the South through the use of coded racial issues, which came to be called the Southern strategy. Meanwhile, newly enfranchised Black voters began supporting Democratic candidates at the 80-90-percent levels, producing Democratic leaders such as Julian Bond and John Lewis of Georgia, and Barbara Jordan of Texas. Just as Martin Luther King had promised, integration had brought about a new day in Southern politics.
In addition to its base among northern newcomers, businessmen and the white middle-class, Republicans attracted strong majorities among evangelical Christians, who prior to the 1980s were largely apolitical. Exit polls in the 2004 presidential election showed that Bush led Kerry by 70–30% among Southern whites, who comprised 71% of the voters. Kerry had a 90–9 lead among the 18% of Southern voters who were black. One-third of the Southern voters said they were white evangelicals; they voted for Bush by 80–20.
http://en.wikipedia.org/wiki/Politics_of_the_Southern_United_States