Why did Southern Democrats often fight against civil rights?

There were multiple reasons why Southern Democrats often fought against civil rights. One factor is that they didn’t want to alter the social, political, and economic structure of the South.
Many Southern Democrats believed that whites were superior to African Americans. They felt that any changes brought about by civil rights laws, rules, or actions would create equality between the races in the South. They wanted to keep African Americans in a position of inferiority, and there were several ways to accomplish this. The public facilities for African Americans were usually inferior to those of whites. The same was true for the education that African American children were receiving. By denying African Americans the right to vote, it would make it harder for them to elect leaders who could bring about changes in the South.
Southern Democrats felt that opposing civil rights changes would likely keep in place the policies that allowed whites to remain in control and in power while keeping African Americans in an inferior position.