R H (Richard Henry) Tawney wrote his most important work, Religion and the Rise of Capitalism, in 1926 after he had given up trying to be elected to parliament. He stood for Labour in Rochdale (1919), Tottenham South (1922) and Swindon (1924).
Albert Frederick Pollard wrote one of the most important books about the institution, The Evolution of Parliament, in 1920 and then failed to be elected to serve there in 1922, 1923 and 1924 as a Liberal candidate for London University. His main consolation was probably beating H G Wells into third place in the first two of these contests.
A L Rowse, who went from being the country's leading scholar of Elizabethan England to being an expert specifically on Shakespeare, moved from third to second in his two contests for Labour in Penryn and Falmouth (1931 and 1935), but the outbreak of the Second World War denied him a third chance and he never stood again.