It was an excuse, it was simply a manifestation of that extreme right-wing conservative attitude that was beginning to grow stronger and stronger. And since that time, we have seen more Republicans elected.
Truman’s efforts were met with strong opposition in Congress. As the Democratic national party began to tend towards a more liberal and multicultural program, conservative southern Democrats scrambled to defend their regional traditions against what they called “Reconstruction-era politics.” Southern politicians who had been staunch Democrats began to drift away from the national party. These southern conservatives were joined by the conservative majority of the Republican Party to form the Conservative Coalition. With the combined strength of officials from both parties, the Conservative Coalition largely controlled Congress from 1939 to 1963 and remained an influential force into the mid-1980s. Southern conservatives served as chairs on many important committees. In these powerful positions, they were able to block numerous legislative bills, which ultimately prolonged discriminatory practices in southern elections until the eventual passage of the 1965 Voting Rights Act.
Tensions within the Democratic party came to a head at the 1948 Democratic national convention when southern conservatives were outvoted in their attempt to weaken civil rights proposals. Instead, the majority voted to protect the civil rights of all Americans, urging Congress to prohibit discrimination in employment and voting. In protest, South Carolina governor Strom Thurmond instigated a walkout of thirty-some southern delegates. In their absence, Truman was nominated the Democratic presidential candidate.
Click HERE to learn more and watch a video about the 1948 Democratic Convention, and Strom Thurmond's reaction to Truman's support of civil rights for African Americans. PBS