Democratic President Harry S. Truman 's support of the civil rights movement , combined with the adoption of a civil rights plank in the 1948 Democratic platform , prompted many Southerners to walk out of the Democratic National Convention and form the Dixiecrat Party . This splinter party played a significant role in the 1948 election ; the Dixiecrat candidate , Strom Thurmond , carried Alabama , Louisiana , Mississippi , and South Carolina . In the elections of 1952 and 1956 , the popular Republican Dwight D. Eisenhower , commander of the Allied armed forces during World War II , carried several Southern states , with especially strong showings in the new suburbs . In 1956 , Eisenhower also carried Louisiana , becoming the first Republican to win the state since Rutherford B. Hayes in 1876 . The rest of the Deep South voted for his Democratic opponent , Adlai Stevenson . The 1948 election also marked Maryland 's permanent defection from the Solid South as the expansion of the federal government led to a population explosion in the state that changed Maryland politically into a Northeastern State
Democratic National Convention
1948 Democratic National Convention
Solid South