Final answer:
The Literary Digest poll in 1936 failed due to its method of polling a select, affluent group and relying on self-selected respondents, leading to a non-representative sample and the overestimation of Alf Landon's support over Franklin Roosevelt's. This highlighted the importance of scientific polling techniques.
Step-by-step explanation:
Why the Literary Digest Failed to Accurately Predict the 1936 Election:
The Literary Digest incorrectly predicted that Alf Landon would defeat Franklin Roosevelt in the 1936 presidential election due to a non-scientific polling method. The Digest sent out opinion cards to a select group of individuals - those with magazine subscriptions, telephone services, or car registrations - which represented a more affluent and potentially biased segment of the population. The pool of respondents was also self-selected, as only some recipients returned their cards. This approach resulted in a misrepresentation of the voting public, as it did not accurately reflect the diversity and opinions of all voters.
Franklin D. Roosevelt's appeal to most Americans, notably his New Deal policies, was underestimated, while Alf Landon's support was overestimated, leading to a misguided prediction. This erroneous forecast showcased the importance of utilizing scientific polling methods that more accurately gauge public opinion by including a representative sample of the electorate and considering various social and economic factors that can influence voting behavior.
Future elections, such as the 1948 election between Thomas Dewey and Harry Truman, demonstrated similar lessons regarding the necessity of scientific, accurate polls and the perils of complacency in predicting election outcomes.