During the German Revolution of 1918–1919, the DHP advocated the implementation of a Free State of Hanover within the Weimar Republic and succeeded in having a plebiscite held in the Prussian Province of Hanover on 19 May 1924. However, the referendum fell short of the one-third threshold required to enact devolution. The defeat hastened the party's decline and in the following years many members joined the rising Nazi Party, others the Catholic Centre. In 1933 the DHP, like other conservative and liberal parties, dissolved to prevent a ban by the Nazi regime.