Final answer:
Herbert Hoover's significant advantage in the 1928 election was the nation's economic prosperity, which was largely associated with the Republican Party and Hoover's own reputation as Secretary of Commerce.
Step-by-step explanation:
Herbert Hoover's most important advantage heading into the election of 1928 was the nation's economic prosperity. The country was experiencing financial success with a confident business community, a favorable balance of trade, and a domestic market that was the envy of the world. Americans of that time associated these prosperous times with the Republican Party, and Hoover's previous role as Secretary of Commerce under Harding and Coolidge helped him capitalize on that association. Despite some signs of economic decline in industries and real estate, the overall sentiment was optimistic, as the country had benefited from post-World War I global financial shifts and was receiving millions in interest payments from allied war loans.
Hoover was seen as the candidate who would continue the policies of 'normalcy' and allow industrial capitalism to grow without government interference, reflecting the desire for steadfastness in the economic approach of the time.