The majority of the Southerners in the Democratic Party were against his policy of expanding civil rights for African Americans
Explanation:
During the administration of then, President Harry S. Truman took various steps to expand civil rights for African Americans. This eventually leads to division in the Democratic Party.
This is evident in the fact that the majority of the Southerners who are not happy about the attempt of President Truman left the Democratic Party, to join another party. The other Southerners that remained also voted against Truman.
This development eventually cost him his second term ambition as President
