Final answer:
The Democratic Party realignment during the Great Depression involved establishing the New Deal Coalition, combining diverse voter groups in support of New Deal programs. This transformation continued until civil rights issues precipitated a shift amongst Southern Democrats towards the Republican Party.
Step-by-step explanation:
During the Great Depression, the Democratic Party underwent a significant realignment. This was marked by the implementation of the New Deal strategies under President Franklin Delano Roosevelt, which were designed to protect consumers, expand the economy, improve the condition of workers, and ease financial strain. The New Deal proved popular with a variety of demographic groups, ultimately transforming the American two-party political system.
The realignment saw the Democrats forming what became known as the New Deal Coalition, which included union workers, African Americans, and religious and ethnic minorities, among others. This coalition largely remained intact until the 1960s when civil rights movements created tensions within the party, eventually causing many Southern Democrats to migrate to the Republican Party as it promoted smaller federal government and state rights.