The party's opposition to World War I caused a sharp decline in membership. Radicals moved further left into the IWW or to the Communist Party USA. Members who supported the war effort quit, ranging from the rank and file to prominent intellectuals such as Walter Lippmann, John Spargo, James Graham Phelps Stokes and William English Walling. Some briefly formed the National Party in an unrealized hope of merging with the remnants of Theodore Roosevelt's Progressive Party and the Prohibition Party. Official membership fell from 83,284 in 1916 to 74,519 in 1918. By 1918, the Socialist Party had won 1,200 political offices, including electing US Representative, 32 state representatives and 79 mayors. It gained new votes in ethnic strongholds such as Milwaukee and New York from conservative German Americans who also opposed the war.