While continuing to serve as the district attorney of Alameda County , Warren emerged as leader of the state Republican Party . He served as the county chairman for Herbert Hoover 's 1932 campaign and , after Franklin D. Roosevelt won that election , he attacked Roosevelt 's New Deal policies . In 1934 , Warren became chairman of the state Republican Party and he took a leading public role in opposing the gubernatorial candidacy of Democrat Upton Sinclair . Warren earned national notoriety in 1936 for leading a successful campaign to elect a slate of unpledged delegates to the 1936 Republican National Convention ; he was motivated largely by his opposition to the influence of Governor Frank Merriam and publisher William Randolph Hearst . In the 1936 presidential election , Warren campaigned on behalf of the unsuccessful Republican nominee , Alf Landon
1936 Republican National Convention
1936 Republican National Convention
Earl Warren