with the election of abraham lincoln (the first republican president) in 1860, the party's success in guiding the union to victory in the american civil war, and the party's role in the abolition of slavery, the republican party largely dominated the national political scene until 1932. in 1912, theodore roosevelt formed the progressive ("bull moose") party after being rejected by the gop and ran unsuccessfully as a third-party presidential candidate calling for social reforms. after 1912, many roosevelt supporters left the party, and the party underwent an ideological shift to the right. the gop lost its congressional majorities during the great depression (1929–1940); under president franklin d. roosevelt, the democrats formed a winning new deal coalition that was dominant from 1932 through 1964.