Final answer:
The Democratic Party faced significant challenges from the Civil Rights Movement, the Great Depression, and the Vietnam War but remained competitive through coalition-building, reforms, and adapting to societal shifts.
Step-by-step explanation:
The Democratic Party has had to overcome several challenges throughout its history to remain competitive in American politics. One such challenge was the Civil Rights Movement, as internal divisions arose on social issues during the late 1950s and early 1960s, causing some Southern Democrats to break away from the party. This shift was accentuated with the rise of the evangelical movement, which transitioned its support to Ronald Reagan in the 1980 presidential election. Another significant obstacle for Democrats was the Great Depression, which necessitated a change in the party's governing coalition. The New Deal coalition under Franklin Roosevelt united varied groups to support the Democratic Party through the economic crisis. Lastly, the Vietnam War created deep divisions within the Democratic Party and contributed to a rupture of its base in the 1968 election. However, the party implemented reforms to the delegate selection process that ultimately democratized the primary system and broadened its appeal.