Final answer:
William McKinley's victory in the 1896 election represented the decline of the Populists as a national party, as they failed to sway the rapidly urbanizing American electorate and couldn't match the economic conservatism offered by McKinley. While the Populist Party faded, some of their ideas were nonetheless absorbed into mainstream politics by the early 20th century.
Step-by-step explanation:
William McKinley's victory in the election of 1896 marked the end of the Populist movement as a significant force in American politics. McKinley's campaign built on probusiness policies and the explicit maintenance of the gold standard, resonated with bankers, the wealthy, and even some laborers and farmers who feared the economic consequences of inflation and the free silver platform of the Populists. The Populists had aligned with the Democratic candidate William Jennings Bryan, hoping to promote economic reforms that included the introduction of free silver, but their failure to gain enough urban votes and the subsequent McKinley victory illustrated a shift in national attitudes toward more conservative fiscal policies and the value of economic stability.
By 1900, the Populist Party had mostly disappeared on a national level, but some of their ideas lived on through politicians from the two major parties. They elected twenty-two men to the House of Representatives and controlled five senate seats. However, their alignment with the Democrats, their inability to navigate rapidly urbanizing demographics, and a general preference for stability over Populist-oriented reforms after a deep national depression contributed to their decline.
The Populists might not be considered total failures as their spirit and some of their ideas were later adopted by a new group of reformers in the early 20th century.