100% sure its the 1896 election of McKinley :)
The Populist Party lost power in large part as a result of * the 1896 election of McKinley. *
The Populists held a political campaign directed at advancing circumstances for the country's farmers and agrarian artisans. The Populist movement was introduced by the Farmer's Alliance having an agrarian base and the Grange. The People's Party was a legislative party established in 1891 by batons of the Populist campaign. ;
The Populist Party lost power primarily due to the 1896 election of William McKinley. Their decision to support Bryan did not secure enough votes, especially from the urban population. This led to a significant decline in the party's influence after the election.
;